| Message ID | 20230523154747.5429-1-srinivas.kandagatla@linaro.org |
|---|---|
| State | Accepted |
| Commit | 95856d1f3c223c015780fffb8373a827fc4efd2e |
| Headers | show |
| Series | regmap: sdw: check for invalid multi-register writes config | expand |
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 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.
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; }
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(+)