The first argument for kcalloc or kmalloc_array should be thenumber of elements. sizeof() as the first argument is generallywrong.

See:https://www.kernel.org/doc/html/latest/core-api/memory-allocation.html

The allocation style is bad. In general for family ofallocation functions using sizeof() to get memory size,constructs like:

p = alloc(sizeof(struct foo), ...)

should be:

p = alloc(sizeof(*p), ...)

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#allocating-memory

Prefer kmalloc_array/kcalloc over kmalloc/kzalloc with asizeof multiply.

See:https://www.kernel.org/doc/html/latest/core-api/memory-allocation.html

Architecture specific defines should be avoided whereverpossible.

Whenever asm/file.h is included and linux/file.h exists, aconversion can be made when linux/file.h includes asm/file.h.However this is not always the case (See signal.h).This message type is emitted only for includes from arch/.

BUG() orBUG_ON() should be avoided totally.UseWARN() andWARN_ON() instead, and handle the “impossible”error condition as gracefully as possible.

See:https://www.kernel.org/doc/html/latest/process/deprecated.html#bug-and-bug-on

Thesimple_strtol(),simple_strtoll(),simple_strtoul(), andsimple_strtoull() functions explicitly ignore overflows, whichmay lead to unexpected results in callers. The respectivekstrtol(),kstrtoll(),kstrtoul(), andkstrtoull() functions tend to be thecorrect replacements.

See:https://www.kernel.org/doc/html/latest/process/deprecated.html#simple-strtol-simple-strtoll-simple-strtoul-simple-strtoull

Use of __constant_<foo> form is discouraged for the following functions:

__constant_cpu_to_be[x]__constant_cpu_to_le[x]__constant_be[x]_to_cpu__constant_le[x]_to_cpu__constant_htons__constant_ntohs

Using any of these outside of include/uapi/ is not preferred as using thefunction without __constant_ is identical when the argument is aconstant.

In big endian systems, the macros like __constant_cpu_to_be32(x) andcpu_to_be32(x) expand to the same expression:

#define __constant_cpu_to_be32(x) ((__force __be32)(__u32)(x))#define __cpu_to_be32(x)          ((__force __be32)(__u32)(x))

In little endian systems, the macros __constant_cpu_to_be32(x) andcpu_to_be32(x) expand to __constant_swab32 and __swab32. __swab32has a __builtin_constant_p check:

#define __swab32(x)                               \  (__builtin_constant_p((__u32)(x)) ?     \  ___constant_swab32(x) :                 \  __fswab32(x))

So ultimately they have a special case for constants.Similar is the case with all of the macros in the list. Thususing the __constant_... forms are unnecessarily verbose andnot preferred outside of include/uapi.

See:https://lore.kernel.org/lkml/1400106425.12666.6.camel@joe-AO725/

Usage of a deprecated RCU API is detected. It is recommended to replaceold flavourful RCU APIs by their new vanilla-RCU counterparts.

The full list of available RCU APIs can be viewed from the kernel docs.

See:https://www.kernel.org/doc/html/latest/RCU/whatisRCU.html#full-list-of-rcu-apis

The function names used in DEVICE_ATTR is unusual.Typically, the store and show functions are used with <attr>_store and<attr>_show, where <attr> is a named attribute variable of the device.

Consider the following examples:

static DEVICE_ATTR(type, 0444, type_show, NULL);static DEVICE_ATTR(power, 0644, power_show, power_store);

The function names should preferably follow the above pattern.

See:https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes

The DEVICE_ATTR_RO(name) helper macro can be used instead ofDEVICE_ATTR(name, 0444, name_show, NULL);

Note that the macro automatically appends _show to the namedattribute variable of the device for the show method.

See:https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes

The DEVICE_ATTR_RW(name) helper macro can be used instead ofDEVICE_ATTR(name, 0644, name_show, name_store);

Note that the macro automatically appends _show and _store to thenamed attribute variable of the device for the show and store methods.

See:https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes

The DEVICE_AATR_WO(name) helper macro can be used instead ofDEVICE_ATTR(name, 0200, NULL, name_store);

Note that the macro automatically appends _store to thenamed attribute variable of the device for the store method.

See:https://www.kernel.org/doc/html/latest/driver-api/driver-model/device.html#attributes

Commit d91bff3011cf (“proc/sysctl: add shared variables for rangecheck”) added some shared const variables to be used instead of a localcopy in each source file.

Consider replacing the sysctl range checking value with the sharedone in include/linux/sysctl.h. The following conversion scheme maybe used:

&zero     ->  SYSCTL_ZERO&one      ->  SYSCTL_ONE&int_max  ->  SYSCTL_INT_MAX

See:

1. https://lore.kernel.org/lkml/20190430180111.10688-1-mcroce@redhat.com/

2. https://lore.kernel.org/lkml/20190531131422.14970-1-mcroce@redhat.com/

ENOSYS means that a nonexistent system call was called.Earlier, it was wrongly used for things like invalid operations onotherwise valid syscalls. This should be avoided in new code.

See:https://lore.kernel.org/lkml/5eb299021dec23c1a48fa7d9f2c8b794e967766d.1408730669.git.luto@amacapital.net/

ENOTSUPP is not a standard error code and should be avoided in new patches.EOPNOTSUPP should be used instead.

See:https://lore.kernel.org/netdev/20200510182252.GA411829@lunn.ch/

EXPORT_SYMBOL should immediately follow the symbol to be exported.

in_atomic() is not for driver use so any such use is reported as an ERROR.Alsoin_atomic() is often used to determine if sleeping is permitted,but it is not reliable in this use model. Therefore its use isstrongly discouraged.

However,in_atomic() is ok for core kernel use.

See:https://lore.kernel.org/lkml/20080320201723.b87b3732.akpm@linux-foundation.org/

The lockdep_no_validate class was added as a temporary measure toprevent warnings on conversion of device->sem to device->mutex.It should not be used for any other purpose.

See:https://lore.kernel.org/lkml/1268959062.9440.467.camel@laptop/

The #include statement has a malformed path. This has happenedbecause the author has included a double slash “//” in the pathnameaccidentally.

lockdep_assert_held() annotations should be preferred overassertions based onspin_is_locked()

See:https://www.kernel.org/doc/html/latest/locking/lockdep-design.html#annotations

No #include statements in include/uapi should use a uapi/ path.

usleep_range() should be preferred overudelay(). The proper way ofusingusleep_range() is mentioned in the kernel docs.

The comment style is incorrect. The preferred style for multi-line comments is:

/* * This is the preferred style * for multi line comments. */

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting

C99 style single line comments (//) should not be used.Prefer the block comment style instead.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#commenting

Applications ofdata_race() should have a comment so as to document thereasoning behind why it was deemed safe.

See:https://lore.kernel.org/lkml/20200401101714.44781-1-elver@google.com/

Kernel maintainers reject new instances of the GPL boilerplate paragraphdirecting people to write to the FSF for a copy of the GPL, since theFSF has moved in the past and may do so again.So do not write paragraphs about writing to the Free Software Foundation’smailing address.

See:https://lore.kernel.org/lkml/20131006222342.GT19510@leaf/

Historically, the RGMII PHY modes specified in Device Trees have beenused inconsistently, often referring to the usage of delays on the PHYside rather than describing the board.

PHY modes “rgmii”, “rgmii-rxid” and “rgmii-txid” modes require the clocksignal to be delayed on the PCB; this unusual configuration should bedescribed in a comment. If they are not (meaning that the delay is realizedinternally in the MAC or PHY), “rgmii-id” is the correct PHY mode.

The signed-off-by line does not fall in line with the standardsspecified by the community.

See:https://www.kernel.org/doc/html/latest/process/submitting-patches.html#developer-s-certificate-of-origin-1-1

The email format for stable is incorrect.Some valid options for stable address are:

1. stable@vger.kernel.org2. stable@kernel.org

For adding version info, the following comment style should be used:

stable@vger.kernel.org # version info

Commit log lines starting with a ‘#’ are ignored by git ascomments. To solve this problem addition of a single spaceinfront of the log line is enough.

The patch is missing a commit description. A briefdescription of the changes made by the patch should be added.

See:https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes

Naming the tool that found the issue is not very useful in thesubject line. A good subject line summarizes the change thatthe patch brings.

See:https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes

The author’s email does not match with that in the Signed-off-by:line(s). This can be sometimes caused due to an improperly configuredemail client.

This message is emitted due to any of the following reasons:

- The email names do not match.- The email addresses do not match.- The email subaddresses do not match.- The email comments do not match.

The patch is missing a Signed-off-by line. A signed-off-byline should be added according to Developer’s certificate ofOrigin.

See:https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin

The author of the patch has not signed off the patch. It isrequired that a simple sign off line should be present at theend of explanation of the patch to denote that the author haswritten it or otherwise has the rights to pass it on as an opensource patch.

See:https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin

Avoid having diff content in commit message.This causes problems when one tries to apply a file containing boththe changelog and the diff because patch(1) tries to apply the diffwhich it found in the changelog.

See:https://lore.kernel.org/lkml/20150611134006.9df79a893e3636019ad2759e@linux-foundation.org/

To be picked up by gerrit, the footer of the commit message mighthave a Change-Id like:

Change-Id: Ic8aaa0728a43936cd4c6e1ed590e01ba8f0fbf5bSigned-off-by: A. U. Thor <author@example.com>

The Change-Id line must be removed before submitting.

The proper way to reference a commit id is:commit <12+ chars of sha1> (“<title line>”)

An example may be:

Commit e21d2170f36602ae2708 ("video: remove unnecessaryplatform_set_drvdata()") removed the unnecessaryplatform_set_drvdata(), but left the variable "dev" unused,delete it.

See:https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes

The Fixes: tag is malformed or does not follow the community conventions.This can occur if the tag have been split into multiple lines (e.g., whenpasted in an email program with word wrapping enabled).

See:https://www.kernel.org/doc/html/latest/process/submitting-patches.html#describe-your-changes

Do not use assignments in if condition.Example:

if ((foo = bar(...)) < BAZ) {

should be written as:

foo = bar(...);if (foo < BAZ) {

Comparisons of A to true and false are better writtenas A and !A.

See:https://lore.kernel.org/lkml/1365563834.27174.12.camel@joe-AO722/

Comparisons to NULL in the form (foo == NULL) or (foo != NULL)are better written as (!foo) and (foo).

Comparisons with a constant or upper case identifier on the leftside of the test should be avoided.

Code indent should use tabs instead of spaces.Outside of comments, documentation and Kconfig,spaces are never used for indentation.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#indentation

Indentation with 6 or more tabs usually indicate overly indentedcode.

It is suggested to refactor excessive indentation ofif/else/for/do/while/switch statements.

See:https://lore.kernel.org/lkml/1328311239.21255.24.camel@joe2Laptop/

switch should be at the same indent as case.Example:

switch (suffix) {case 'G':case 'g':        mem <<= 30;        break;case 'M':case 'm':        mem <<= 20;        break;case 'K':case 'k':        mem <<= 10;        fallthrough;default:        break;}

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#indentation

The line has exceeded the specified maximum length.To use a different maximum line length, the --max-line-length=n optionmay be added while invoking checkpatch.

Earlier, the default line length was 80 columns.Commit bdc48fa11e46(“checkpatch/coding-style: deprecate 80-column warning”) increased thelimit to 100 columns. This is not a hard limit either and it’spreferable to stay within 80 columns whenever possible.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-strings

A string starts before but extends beyond the maximum line length.To use a different maximum line length, the --max-line-length=n optionmay be added while invoking checkpatch.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-strings

A comment starts before but extends beyond the maximum line length.To use a different maximum line length, the --max-line-length=n optionmay be added while invoking checkpatch.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#breaking-long-lines-and-strings

Quoted strings that appear as messages in userspace and can begrepped, should not be split across multiple lines.

See:https://lore.kernel.org/lkml/20120203052727.GA15035@leaf/

A single dereferencing identifier spanned on multiple lines like:

struct_identifier->member[index].member = <foo>;

is generally hard to follow. It can easily lead to typos and so makesthe code vulnerable to bugs.

If fixing the multiple line dereferencing leads to an 80 columnviolation, then either rewrite the code in a more simple way or if thestarting part of the dereferencing identifier is the same and used atmultiple places then store it in a temporary variable, and use thattemporary variable only at all the places. For example, if there aretwo dereferencing identifiers:

member1->member2->member3.foo1;member1->member2->member3.foo2;

then store the member1->member2->member3 part in a temporary variable.It not only helps to avoid the 80 column violation but also reducesthe program size by removing the unnecessary dereferences.

But if none of the above methods work then ignore the 80 columnviolation because it is much easier to read a dereferencing identifieron a single line.

Trailing statements (for example after any conditional) should beon the next line.Statements, such as:

if (x == y) break;

should be:

if (x == y)        break;

The ARRAY_SIZE(foo) macro should be preferred oversizeof(foo)/sizeof(foo[0]) for finding number of elements in anarray.

The macro is defined in include/linux/kernel.h:

#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))

Function prototypes don’t need to be declared extern in .hfiles. It’s assumed by the compiler and is unnecessary.

Local symbol names that are prefixed with.L should be avoided,as this has special meaning for the assembler; a symbol entry willnot be emitted into the symbol table. This can preventobjtoolfrom generating correct unwind info.

Symbols with STB_LOCAL binding may still be used, and.L prefixedlocal symbol names are still generally usable within a function,but.L prefixed local symbol names should not be used to denotethe beginning or end of code regions viaSYM_CODE_START_LOCAL/SYM_CODE_END

Defines like: 1 << <digit> could be BIT(digit).TheBIT() macro is defined via include/linux/bits.h:

#define BIT(nr)         (1UL << (nr))

When a variable is tagged with the __read_mostly annotation, it is asignal to the compiler that accesses to the variable will be mostlyreads and rarely(but NOT never) a write.

const __read_mostly does not make any sense as const data is alreadyread-only. The __read_mostly annotation thus should be removed.

It is generally desirable that building the same source code withthe same set of tools is reproducible, i.e. the output is alwaysexactly the same.

The kernel doesnot use the__DATE__ and__TIME__ macros,and enables warnings if they are used as they can lead tonon-deterministic builds.

See:https://www.kernel.org/doc/html/latest/kbuild/reproducible-builds.html#timestamps

The ARCH_HAS_xyz and ARCH_HAVE_xyz patterns are wrong.

For big conceptual features use Kconfig symbols instead. And forsmaller things where we have compatibility fallback functions butwant architectures able to override them with optimized ones, weshould either use weak functions (appropriate for some cases), orthe symbol that protects them should be the same symbol we use.

See:https://lore.kernel.org/lkml/CA+55aFycQ9XJvEOsiM3txHL5bjUc8CeKWJNR_H+MiicaddB42Q@mail.gmail.com/

do {} while(0) macros should not have a trailing semicolon.

Const init definitions should use __initconst instead of__initdata.

Similarly init definitions without const require a separateuse of const.

The inline keyword should sit between storage class and type.

For example, the following segment:

inline static int example_function(void){        ...}

should be:

static inline int example_function(void){        ...}

It is possible to use section markers on variables in a waywhich gcc doesn’t understand (or at least not the way thedeveloper intended):

static struct __initdata samsung_pll_clock exynos4_plls[nr_plls] = {

does not put exynos4_plls in the .initdata section. The __initdatamarker can be virtually anywhere on the line, except right after“struct”. The preferred location is before the “=” sign if there isone, or before the trailing “;” otherwise.

See:https://lore.kernel.org/lkml/1377655732.3619.19.camel@joe-AO722/

Macros with multiple statements should be enclosed in ado - while block. Same should also be the case for macrosstarting withif to avoid logic defects:

#define macrofun(a, b, c)                 \  do {                                    \          if (a == 5)                     \                  do_this(b, c);          \  } while (0)

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#macros-enums-and-rtl

Use thefallthrough; pseudo keyword instead of/* fallthrough */ like comments.

Macro definition should not end with a semicolon. The macroinvocation style should be consistent with function calls.This can prevent any unexpected code paths:

#define MAC do_something;

If this macro is used within a if else statement, like:

if (some_condition)        MAC;else        do_something;

Then there would be a compilation error, because when the macro isexpanded there are two trailing semicolons, so the else branch getsorphaned.

See:https://lore.kernel.org/lkml/1399671106.2912.21.camel@joe-AO725/

If function-like macros do not utilize a parameter, it might resultin a build warning. We advocate for utilizing static inline functionsto replace such macros.For example, for a macro such as the one below:

#define test(a) do { } while (0)

there would be a warning like below:

WARNING: Argument 'a' is not used in function-like macro.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#macros-enums-and-rtl

For the multi-statement macros, it is necessary to use the do-whileloop to avoid unpredictable code paths. The do-while loop helps togroup the multiple statements into a single one so that afunction-like macro can be used as a function only.

But for the single statement macros, it is unnecessary to use thedo-while loop. Although the code is syntactically correct but usingthe do-while loop is redundant. So remove the do-while loop for singlestatement macros.

Using weak declarations like __attribute__((weak)) or __weakcan have unintended link defects. Avoid using them.

Avoid CamelCase Identifiers.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#naming

Usingconst <type> const * is generally meant to bewrittenconst <type> * const.

Using const is generally a good idea. Checkpatch readsa list of frequently used structs that are always oralmost always constant.

The existing structs list can be viewed fromscripts/const_structs.checkpatch.

See:https://lore.kernel.org/lkml/alpine.DEB.2.10.1608281509480.3321@hadrien/

Embedded function names are less appropriate to use asrefactoring can cause function renaming. Prefer the use of“%s”, __func__ to embedded function names.

Note that this does not work with -f (--file) checkpatch optionas it depends on patch context providing the function name.

This warning is emitted due to any of the following reasons:

1. Arguments for the function declaration do not followthe identifier name. Example:

   void foo(int bar, int baz)

   This should be corrected to:

   void foo(int bar, int baz)

2. Some arguments for the function definition do nothave an identifier name. Example:

   void foo(int)

   All arguments should have identifier names.

Function declarations without arguments like:

int foo()

should be:

int foo(void)

Global variables should not be initialized explicitly to0 (or NULL, false, etc.). Your compiler (or rather yourloader, which is responsible for zeroing out the relevantsections) automatically does it for you.

Static variables should not be initialized explicitly to zero.Your compiler (or rather your loader) automatically doesit for you.

Multiple assignments on a single line makes the code unnecessarilycomplicated. So on a single line assign value to a single variableonly, this makes the code more readable and helps avoid typos.

return is not a function and as such doesn’t need parentheses:

return (bar);

can simply be:

return bar;

Pointers with __free attribute should be declared at the place of useand initialized (see include/linux/cleanup.h). In this casedeclarations at the top of the function rule can be relaxed. Not doingso may lead to undefined behavior as the memory assigned (garbage,in case not initialized) to the pointer is freed automatically whenthe pointer goes out of scope.

Also see:https://lore.kernel.org/lkml/58fd478f408a34b578ee8d949c5c4b4da4d4f41d.camel@HansenPartnership.com/

Example:

type var __free(free_func);... // var not used, but, in future someone might add a return herevar = malloc(var_size);...

should be initialized as:

...type var __free(free_func) = malloc(var_size);...

The permissions used in DEVICE_ATTR are unusual.Typically only three permissions are used - 0644 (RW), 0444 (RO)and 0200 (WO).

See:https://www.kernel.org/doc/html/latest/filesystems/sysfs.html#attributes

There is no reason for source files to be executable. The executablebit can be removed safely.

Exporting world writable sysfs/debugfs files is usually a bad thing.When done arbitrarily they can introduce serious security bugs.In the past, some of the debugfs vulnerabilities would seemingly allowany local user to write arbitrary values into device registers - asituation from which little good can be expected to emerge.

See:https://lore.kernel.org/linux-arm-kernel/cover.1296818921.git.segoon@openwall.com/

Permission bits should use 4 digit octal permissions (like 0700 or 0444).Avoid using any other base like decimal.

Permission bits in the octal form are more readable and easier tounderstand than their symbolic counterparts because many command-linetools use this notation. Experienced kernel developers have been usingthese traditional Unix permission bits for decades and so they find iteasier to understand the octal notation than the symbolic macros.For example, it is harder to read S_IWUSR|S_IRUGO than 0644, whichobscures the developer’s intent rather than clarifying it.

See:https://lore.kernel.org/lkml/CA+55aFw5v23T-zvDZp-MmD_EYxF8WbafwwB59934FV7g21uMGQ@mail.gmail.com/

Assignment operators should not be written at the start of aline but should follow the operand at the previous line.

The placement of braces is stylistically incorrect.The preferred way is to put the opening brace last on the line,and put the closing brace first:

if (x is true) {        we do y}

This applies for all non-functional blocks.However, there is one special case, namely functions: they have theopening brace at the beginning of the next line, thus:

int function(int x){        body of function}

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces

Whitespace before opening bracket ‘[’ is prohibited.There are some exceptions:

1. With a type on the left:

   int [] a;

2. At the beginning of a line for slice initialisers:

   [0...10] = 5,

3. Inside a curly brace:

   = { [0...10] = 5 }

Concatenated elements should have a space in between.Example:

printk(KERN_INFO"bar");

should be:

printk(KERN_INFO "bar");

else { should follow the closing block} on the same line.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces

Vertical space is wasted given the limited number of lines aneditor window can display when multiple blank lines are used.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces

The opening brace should be following the function definitions on thenext line. For any non-functional block it should be on the same lineas the last construct.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces

When using pointer data or a function that returns a pointer type,the preferred use of * is adjacent to the data name or function nameand not adjacent to the type name.Examples:

char *linux_banner;unsigned long long memparse(char *ptr, char **retptr);char *match_strdup(substring_t *s);

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces

Whitespace style used in the kernel sources is described in kernel docs.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces

Trailing whitespace should always be removed.Some editors highlight the trailing whitespace and cause visualdistractions when editing files.

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#spaces

Parentheses are not required in the following cases:

1. Function pointer uses:

   (foo->bar)();

could be:

foo->bar();

2. Comparisons in if:

   if ((foo->bar) && (foo->baz))if ((foo == bar))

could be:

if (foo->bar && foo->baz)if (foo == bar)

3. addressof/dereference single Lvalues:

   &(foo->bar)*(foo->bar)

could be:

&foo->bar*foo->bar

while should follow the closing bracket on the same line:

do {        ...} while(something);

See:https://www.kernel.org/doc/html/latest/process/coding-style.html#placing-braces-and-spaces

Kconfig symbols should have a help text which fully describesit.

The patch seems to be corrupted or lines are wrapped.Please regenerate the patch file before sending it to the maintainer.

Since linux moved to git, the CVS markers are no longer used.So, CVS style keywords ($Id$, $Revision$, $Log$) should not beadded.

switch default case is sometimes written as “default:;”. This cancause new cases added below default to be defective.

A “break;” should be added after empty default statement to avoidunwanted fallthrough.

For DOS-formatted patches, there are extra ^M symbols at the end ofthe line. These should be removed.

DT bindings moved to a json-schema based format instead offreeform text.

See:https://www.kernel.org/doc/html/latest/devicetree/bindings/writing-schema.html

Devicetree bindings should be their own patch. This is becausebindings are logically independent from a driver implementation,they have a different maintainer (even though they oftenare applied via the same tree), and it makes for a cleaner history in theDT only tree created with git-filter-branch.

See:https://www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters

Embedding the complete filename path inside the file isn’t particularlyuseful as often the path is moved around and becomes incorrect.

Whenever files are added, moved, or deleted, the MAINTAINERS filepatterns can be out of sync or outdated.

So MAINTAINERS might need updating in these cases.

The memset use appears to be incorrect. This may be caused due tobadly ordered parameters. Please recheck the usage.

The patch file does not appear to be in unified-diff format. Pleaseregenerate the patch file before sending it to the maintainer.

Detects unhandled placeholder text left in cover letters or commit headers/logs.Common placeholders include lines like:

*** SUBJECT HERE ****** BLURB HERE ***

These typically come from autogenerated templates. Replace them with a propersubject and description before sending.

Prefixing 0x with decimal output is defective and should be corrected.

The source file is missing or has an improper SPDX identifier tag.The Linux kernel requires the precise SPDX identifier in all source files,and it is thoroughly documented in the kernel docs.

See:https://www.kernel.org/doc/html/latest/process/license-rules.html

Some words may have been misspelled. Consider reviewing them.