On Tue, Jul 30, 2019 at 10:59 AM Nicolin Chen <nicoleotsuka@xxxxxxxxx> wrote: > > On Mon, Jul 29, 2019 at 09:20:01PM +0100, Mark Brown wrote: > > On Mon, Jul 29, 2019 at 10:57:43PM +0300, Daniel Baluta wrote: > > > On Mon, Jul 29, 2019 at 10:42 PM Nicolin Chen <nicoleotsuka@xxxxxxxxx> wrote: > > > > On Sun, Jul 28, 2019 at 10:24:23PM +0300, Daniel Baluta wrote: > > > > > > > @@ -704,7 +711,14 @@ static bool fsl_sai_readable_reg(struct device *dev, unsigned int reg) > > > > > case FSL_SAI_TCR3: > > > > > case FSL_SAI_TCR4: > > > > > case FSL_SAI_TCR5: > > > > > - case FSL_SAI_TFR: > > > > > + case FSL_SAI_TFR0: > > > > > > A tricky thing here is that those SAI instances on older SoC don't > > > > support multi data lines physically, while seemly having registers > > > > pre-defined. So your change doesn't sound doing anything wrong to > > > > them at all, I am still wondering if it is necessary to apply them > > > > to newer compatible only though, as for older compatibles of SAI, > > > > these registers would be useless and confusing if being exposed. > > > > > > What do you think? > > > > > Yes, I thought about this too. But, I tried to keep the code as short > > > as possible and technically it is not wrong. When 1 data line is supported > > > for example application will only care about TDR0, TFR0, etc. > > > > So long as it's safe to read the registers (you don't get a bus error or > > anything) I'd say it's more trouble than it's worth to have separate > > regmap configuations just for this. The main reasons for restricting > > readability are where there's physical problems with doing the reads or > > to keep the size of the debugfs files under control for usability and > > performance reasons. > > Thanks for the input, Mark. > > Daniel, did you get a chance to test it on older SoCs? At least > nothing breaks like bus errors? Tested on imx6sx-sdb, everything looks good. No bus errors.
