| Message ID | 20230523154747.5429-1-srinivas.kandagatla@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| 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 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. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark
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(+)