https://github.com/torvalds/linux
Revision 98a226ed21949601b270f7ea20abc9f72f7b0be9 authored by Takashi Iwai on 10 June 2015, 08:27:00 UTC, committed by Takashi Iwai on 10 June 2015, 08:31:10 UTC
Along with the transition to regmap for managing the cached parameter
reads, the caps overwrite was also moved to regmap cache.  The cache
change itself works, but it still tries to write the non-existing verb
(the HDA parameter is read-only) wrongly.  It's harmless in most
cases, but some chips are picky and may result in the codec
communication stall.

This patch avoids it just by adding the missing flag check in
reg_write ops.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
1 parent 132bd96
Raw File
Tip revision: 98a226ed21949601b270f7ea20abc9f72f7b0be9 authored by Takashi Iwai on 10 June 2015, 08:27:00 UTC
ALSA: hda - Don't actually write registers for caps overwrites
Tip revision: 98a226e
bug.h
#ifndef _LINUX_BUG_H
#define _LINUX_BUG_H

#include <asm/bug.h>
#include <linux/compiler.h>

enum bug_trap_type {
	BUG_TRAP_TYPE_NONE = 0,
	BUG_TRAP_TYPE_WARN = 1,
	BUG_TRAP_TYPE_BUG = 2,
};

struct pt_regs;

#ifdef __CHECKER__
#define BUILD_BUG_ON_NOT_POWER_OF_2(n) (0)
#define BUILD_BUG_ON_ZERO(e) (0)
#define BUILD_BUG_ON_NULL(e) ((void*)0)
#define BUILD_BUG_ON_INVALID(e) (0)
#define BUILD_BUG_ON_MSG(cond, msg) (0)
#define BUILD_BUG_ON(condition) (0)
#define BUILD_BUG() (0)
#else /* __CHECKER__ */

/* Force a compilation error if a constant expression is not a power of 2 */
#define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))

/* Force a compilation error if condition is true, but also produce a
   result (of value 0 and type size_t), so the expression can be used
   e.g. in a structure initializer (or where-ever else comma expressions
   aren't permitted). */
#define BUILD_BUG_ON_ZERO(e) (sizeof(struct { int:-!!(e); }))
#define BUILD_BUG_ON_NULL(e) ((void *)sizeof(struct { int:-!!(e); }))

/*
 * BUILD_BUG_ON_INVALID() permits the compiler to check the validity of the
 * expression but avoids the generation of any code, even if that expression
 * has side-effects.
 */
#define BUILD_BUG_ON_INVALID(e) ((void)(sizeof((__force long)(e))))

/**
 * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied
 *		      error message.
 * @condition: the condition which the compiler should know is false.
 *
 * See BUILD_BUG_ON for description.
 */
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)

/**
 * BUILD_BUG_ON - break compile if a condition is true.
 * @condition: the condition which the compiler should know is false.
 *
 * If you have some code which relies on certain constants being equal, or
 * some other compile-time-evaluated condition, you should use BUILD_BUG_ON to
 * detect if someone changes it.
 *
 * The implementation uses gcc's reluctance to create a negative array, but gcc
 * (as of 4.4) only emits that error for obvious cases (e.g. not arguments to
 * inline functions).  Luckily, in 4.3 they added the "error" function
 * attribute just for this type of case.  Thus, we use a negative sized array
 * (should always create an error on gcc versions older than 4.4) and then call
 * an undefined function with the error attribute (should always create an
 * error on gcc 4.3 and later).  If for some reason, neither creates a
 * compile-time error, we'll still have a link-time error, which is harder to
 * track down.
 */
#ifndef __OPTIMIZE__
#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
#else
#define BUILD_BUG_ON(condition) \
	BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition)
#endif

/**
 * BUILD_BUG - break compile if used.
 *
 * If you have some code that you expect the compiler to eliminate at
 * build time, you should use BUILD_BUG to detect if it is
 * unexpectedly used.
 */
#define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")

#endif	/* __CHECKER__ */

#ifdef CONFIG_GENERIC_BUG
#include <asm-generic/bug.h>

static inline int is_warning_bug(const struct bug_entry *bug)
{
	return bug->flags & BUGFLAG_WARNING;
}

const struct bug_entry *find_bug(unsigned long bugaddr);

enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs);

/* These are defined by the architecture */
int is_valid_bugaddr(unsigned long addr);

#else	/* !CONFIG_GENERIC_BUG */

static inline enum bug_trap_type report_bug(unsigned long bug_addr,
					    struct pt_regs *regs)
{
	return BUG_TRAP_TYPE_BUG;
}

#endif	/* CONFIG_GENERIC_BUG */
#endif	/* _LINUX_BUG_H */
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