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.nikula@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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