[PATCH] regmap: sdw: check for invalid multi-register writes config
SoundWire code as it is only supports Bulk register writes and it does not support multi-register writes.
Any drivers that set can_multi_write and use regmap_multi_reg_write() will easily endup with programming the hardware incorrectly without any errors.
So, add this check in bus code to be able to validate the drivers config.
Fixes: 522272047dc6 ("regmap: sdw: Remove 8-bit value size restriction") Signed-off-by: Srinivas Kandagatla srinivas.kandagatla@linaro.org --- drivers/base/regmap/regmap-sdw.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/base/regmap/regmap-sdw.c b/drivers/base/regmap/regmap-sdw.c index 09899ae99fc1..159c0b740b00 100644 --- a/drivers/base/regmap/regmap-sdw.c +++ b/drivers/base/regmap/regmap-sdw.c @@ -59,6 +59,10 @@ static int regmap_sdw_config_check(const struct regmap_config *config) if (config->pad_bits != 0) return -ENOTSUPP;
+ /* Only bulk writes are supported not multi-register writes */ + if (config->can_multi_write) + return -ENOTSUPP; + return 0; }
On Tue, May 23, 2023 at 04:47:47PM +0100, Srinivas Kandagatla wrote:
- /* Only bulk writes are supported not multi-register writes */
- if (config->can_multi_write)
return -ENOTSUPP;
This doesn't seem like the right fix - I'd expect us to simply choose not to use multiple writes, with an additional flag/check for bus support.
On 23/05/2023 17:58, Mark Brown wrote:
On Tue, May 23, 2023 at 04:47:47PM +0100, Srinivas Kandagatla wrote:
- /* Only bulk writes are supported not multi-register writes */
- if (config->can_multi_write)
return -ENOTSUPP;This doesn't seem like the right fix - I'd expect us to simply choose not to use multiple writes, with an additional flag/check for bus support.
Is there a way to check if bus support multi-register writes?
All I can see from the code is that regmap can_multi_write is set based on regmap_config from device and write callback from bus.
--srini
On Tue, May 23, 2023 at 06:13:25PM +0100, Srinivas Kandagatla wrote:
On 23/05/2023 17:58, Mark Brown wrote:
On Tue, May 23, 2023 at 04:47:47PM +0100, Srinivas Kandagatla wrote:
- /* Only bulk writes are supported not multi-register writes */
- if (config->can_multi_write)
return -ENOTSUPP;
This doesn't seem like the right fix - I'd expect us to simply choose not to use multiple writes, with an additional flag/check for bus support.
Is there a way to check if bus support multi-register writes?
All I can see from the code is that regmap can_multi_write is set based on regmap_config from device and write callback from bus.
No, that'd be the additional flag/check bit - see also my question about if this is something the hardware actually has or not on the CODEC patch.
On Tue, 23 May 2023 16:47:47 +0100, Srinivas Kandagatla wrote:
SoundWire code as it is only supports Bulk register writes and it does not support multi-register writes.
Any drivers that set can_multi_write and use regmap_multi_reg_write() will easily endup with programming the hardware incorrectly without any errors.
So, add this check in bus code to be able to validate the drivers config.
[...]
Applied to
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git for-next
Thanks!
[1/1] regmap: sdw: check for invalid multi-register writes config commit: 95856d1f3c223c015780fffb8373a827fc4efd2e
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
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Thanks, Mark
participants (2)
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Mark Brown -
Srinivas Kandagatla