Re: [PATCH v4 3/5] mmc: sdhci: fix SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN

From: Michał Mirosław
Date: Sat Aug 07 2021 - 10:08:29 EST


On Wed, Aug 04, 2021 at 02:06:55PM +0300, Adrian Hunter wrote:
> On 25/07/21 12:20 pm, Michał Mirosław wrote:
> > Fix returned clock rate for SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN case.
> > This fixes real_div value that was calculated as 1 (meaning no division)
> > instead of 2 with the quirk enabled.
> >
> > Cc: stable@xxxxxxxxxxxxxxx
> > Fixes: d1955c3a9a1d ("mmc: sdhci: add quirk SDHCI_QUIRK_CLOCK_DIV_ZERO_BROKEN")
> > Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
>
> Notwithstanding comment below:
>
> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
[...]
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -1903,9 +1903,12 @@ u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
> >
> > if (!host->clk_mul || switch_base_clk) {
> > /* Version 3.00 divisors must be a multiple of 2. */
> > - if (host->max_clk <= clock)
> > + if (host->max_clk <= clock) {
> > div = 1;
> > - else {
> > + if ((host->quirks2 & SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN)
> > + && host->max_clk <= 25000000)
>
> It is preferred to line break after '&&' and line up e.g.
>
> if ((host->quirks2 & SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN) &&
> host->max_clk <= 25000000)

This was just old code moved, but fixed for next version.

>
>
> > + div = 2;
> > + } else {
> > for (div = 2; div < SDHCI_MAX_DIV_SPEC_300;
> > div += 2) {
> > if ((host->max_clk / div) <= clock)
> > @@ -1914,9 +1917,6 @@ u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
> > }
> > real_div = div;
> > div >>= 1;
> > - if ((host->quirks2 & SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN)
> > - && !div && host->max_clk <= 25000000)
> > - div = 1;
> > }
> > } else {
> > /* Version 2.00 divisors must be a power of 2. */
> >
>