Call stack of regcache_sync calls may not emit any error message even if operation was cancelled due an error in I/O driver. One such a silent error is for instance if I2C bus driver doesn't receive ACK from the I2C device and returns -EREMOTEIO.
Since many users of regcache_sync() don't check and print the error there is no any indication that HW registers are potentially out of sync. Signed-off-by: Jarkko Nikula <[email protected]> --- I noticed this silent failure when doing commit f4821e8e8e95 ("ASoC: rt5640: Do not allow regmap to use bulk read-write operations") but forgot to send a patch. I was thinking should the error prints be in lower level, e.g. _regmap_raw_write, but maybe it's good to have sync errors printed explicitly? --- drivers/base/regmap/regcache.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index 5617da6dc898..f1280dc356d0 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -269,8 +269,11 @@ static int regcache_default_sync(struct regmap *map, unsigned int min, map->cache_bypass = 1; ret = _regmap_write(map, reg, val); map->cache_bypass = 0; - if (ret) + if (ret) { + dev_err(map->dev, "Unable to sync register %#x. %d\n", + reg, ret); return ret; + } dev_dbg(map->dev, "Synced register %#x, value %#x\n", reg, val); } @@ -615,8 +618,11 @@ static int regcache_sync_block_single(struct regmap *map, void *block, ret = _regmap_write(map, regtmp, val); map->cache_bypass = 0; - if (ret != 0) + if (ret != 0) { + dev_err(map->dev, "Unable to sync register %#x. %d\n", + regtmp, ret); return ret; + } dev_dbg(map->dev, "Synced register %#x, value %#x\n", regtmp, val); } @@ -641,6 +647,9 @@ 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 (ret) + dev_err(map->dev, "Unable to sync registers %#x-%#x. %d\n", + base, cur - map->reg_stride, ret); map->cache_bypass = 0; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
