APPLIED: [Trusty/Utopic/Vivid PATCH] regmap: Skip read-only registers in regcache_sync()

[Brad Figg]

On Mon, Apr 27, 2015 at 11:10:08AM +0800, Hui Wang wrote:
> From: Takashi Iwai <tiwai at suse.de>
> 
> BugLink: http://bugs.launchpad.net/bugs/1448830
> 
> regcache_sync() spews warnings when a value was cached for a read-only
> register as it tries to write all registers no matter whether they are
> writable or not.  This patch adds regmap_wrtieable() checks for
> avoiding it in regcache_sync_block_single() and regcache_block_raw().
> 
> Signed-off-by: Takashi Iwai <tiwai at suse.de>
> Signed-off-by: Mark Brown <broonie at kernel.org>
> (cherry picked from commit 4ceba98d3fe204c59e5f63c4d834b45dcfe789f0)
> Signed-off-by: Hui Wang <hui.wang at canonical.com>
> ---
> Recently the kernel alsa hda audio driver was changed to use regmap to
> access registers, and use regcache to restore registers when resume
> from suspend.
> 
> Without this patch, the regcache_sync() can't restore the registers
> successfully since it will immediately return if one of registers is
> read-only. After applying this patch, the regcache_sync() can skip
> the read-only registers and continue accessing the rest registers.
> 
> And if without this patch, the alsa daily dkms can't work well under
> the ubuntu kernels.
>  
>  drivers/base/regmap/regcache.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
> index 154e7a8..4477713 100644
> --- a/drivers/base/regmap/regcache.c
> +++ b/drivers/base/regmap/regcache.c
> @@ -603,7 +603,8 @@ static int regcache_sync_block_single(struct regmap *map, void *block,
>  	for (i = start; i < end; i++) {
>  		regtmp = block_base + (i * map->reg_stride);
>  
> -		if (!regcache_reg_present(cache_present, i))
> +		if (!regcache_reg_present(cache_present, i) ||
> +		    !regmap_writeable(map, regtmp))
>  			continue;
>  
>  		val = regcache_get_val(map, block, i);
> @@ -666,7 +667,8 @@ static int regcache_sync_block_raw(struct regmap *map, void *block,
>  	for (i = start; i < end; i++) {
>  		regtmp = block_base + (i * map->reg_stride);
>  
> -		if (!regcache_reg_present(cache_present, i)) {
> +		if (!regcache_reg_present(cache_present, i) ||
> +		    !regmap_writeable(map, regtmp)) {
>  			ret = regcache_sync_block_raw_flush(map, &data,
>  							    base, regtmp);
>  			if (ret != 0)
> -- 
> 1.9.1
> 
> 
> -- 
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> kernel-team at lists.ubuntu.com
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Applied to Trusty, Utopic, Vivid master-next

-- 
Brad Figg brad.figg at canonical.com http://www.canonical.com