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
stacktrace.c
/*
 * kernel/stacktrace.c
 *
 * Stack trace management functions
 *
 *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
 */
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>

void print_stack_trace(struct stack_trace *trace, int spaces)
{
	int i;

	if (WARN_ON(!trace->entries))
		return;

	for (i = 0; i < trace->nr_entries; i++) {
		printk("%*c", 1 + spaces, ' ');
		print_ip_sym(trace->entries[i]);
	}
}
EXPORT_SYMBOL_GPL(print_stack_trace);

int snprint_stack_trace(char *buf, size_t size,
			struct stack_trace *trace, int spaces)
{
	int i;
	unsigned long ip;
	int generated;
	int total = 0;

	if (WARN_ON(!trace->entries))
		return 0;

	for (i = 0; i < trace->nr_entries; i++) {
		ip = trace->entries[i];
		generated = snprintf(buf, size, "%*c[<%p>] %pS\n",
				1 + spaces, ' ', (void *) ip, (void *) ip);

		total += generated;

		/* Assume that generated isn't a negative number */
		if (generated >= size) {
			buf += size;
			size = 0;
		} else {
			buf += generated;
			size -= generated;
		}
	}

	return total;
}
EXPORT_SYMBOL_GPL(snprint_stack_trace);

/*
 * Architectures that do not implement save_stack_trace_tsk or
 * save_stack_trace_regs get this weak alias and a once-per-bootup warning
 * (whenever this facility is utilized - for example by procfs):
 */
__weak void
save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
{
	WARN_ONCE(1, KERN_INFO "save_stack_trace_tsk() not implemented yet.\n");
}

__weak void
save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
{
	WARN_ONCE(1, KERN_INFO "save_stack_trace_regs() not implemented yet.\n");
}
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