At Tue, 26 Aug 2014 17:03:12 +0300,
Jarkko Nikula wrote:
>
> Commit 75a5f89f635c ("regmap: cache: Write consecutive registers in a single
> block write") expected that autoincrementing writes are supported if
> hardware has a register format which can support raw writes.
>
> This is not necessarily true and thus for instance rbtree sync can fail when
> there is need to sync multiple consecutive registers but block write to
> device fails due not supported autoincrementing writes.
>
> Fix this by spliting raw block sync to series of single register writes for
> devices that don't support autoincrementing writes.
Wouldn't it suffice to correct regmap_can_raw_write() to return false
if map->use_single_rw is set?
Takashi
>
> Signed-off-by: Jarkko Nikula <jarkko.nik...@linux.intel.com>
> ---
> I noticed this with Realtek RT5642 audio codec which didn't resume properly
> since first block write having more data than for single register failed to
> not acknowledged I2C write during regcache_sync(). Chip acknowledges device
> address, register address and two data bytes for its word size registers but
> next data byte is not which then causes aborted I2C transfer and aborted
> register sync.
> ---
> drivers/base/regmap/regcache.c | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
> index 29b4128da0b0..54707e586ac8 100644
> --- a/drivers/base/regmap/regcache.c
> +++ b/drivers/base/regmap/regcache.c
> @@ -629,6 +629,7 @@ static int regcache_sync_block_raw_flush(struct regmap
> *map, const void **data,
> {
> size_t val_bytes = map->format.val_bytes;
> int ret, count;
> + unsigned int i;
>
> if (*data == NULL)
> return 0;
> @@ -640,7 +641,18 @@ static int regcache_sync_block_raw_flush(struct regmap
> *map, const void **data,
>
> map->cache_bypass = 1;
>
> - ret = _regmap_raw_write(map, base, *data, count * val_bytes);
> + if (!map->use_single_rw) {
> + ret = _regmap_raw_write(map, base, *data, count * val_bytes);
> + } else {
> + for (i = 0; i < count; i++) {
> + ret = _regmap_raw_write(map,
> + base + (i * map->reg_stride),
> + *data + (i * val_bytes),
> + val_bytes);
> + if (ret != 0)
> + break;
> + }
> + }
>
> map->cache_bypass = 0;
>
> --
> 2.1.0
>
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