[PATCH 23/38] mmc: sdhci: convert sdhci_set_uhs_signaling() into a library function

[Ulf Hansson]

On 16 June 2014 12:46, Russell King - ARM Linux <linux at arm.linux.org.uk> wrote:
> On Wed, Apr 23, 2014 at 08:08:07PM +0100, Russell King wrote:
>> @@ -1507,25 +1529,7 @@ static void sdhci_do_set_ios(struct sdhci_host *host, struct mmc_ios *ios)
>>                       host->ops->set_clock(host, host->clock);
>>               }
>>
>> -             if (host->ops->set_uhs_signaling)
>> -                     host->ops->set_uhs_signaling(host, ios->timing);
>> -             else {
>> -                     ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> -                     /* Select Bus Speed Mode for host */
>> -                     ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
>> -                     if ((ios->timing == MMC_TIMING_MMC_HS200) ||
>> -                         (ios->timing == MMC_TIMING_UHS_SDR104))
>> -                             ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
>> -                     else if (ios->timing == MMC_TIMING_UHS_SDR12)
>> -                             ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
>> -                     else if (ios->timing == MMC_TIMING_UHS_SDR25)
>> -                             ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
>> -                     else if (ios->timing == MMC_TIMING_UHS_SDR50)
>> -                             ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
>> -                     else if (ios->timing == MMC_TIMING_UHS_DDR50)
>> -                             ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
>> -                     sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
>> -             }
>> +             host->ops->set_uhs_signaling(host, ios->timing);
>>
>>               if (!(host->quirks2 & SDHCI_QUIRK2_PRESET_VALUE_BROKEN) &&
>>                               ((ios->timing == MMC_TIMING_UHS_SDR12) ||
>
> Whoever decided to poorly pick these patches up against my will has
> slightly messed this patch up - whereas my original patch left the
> code correctly formatted, when whoever applied this patch did so, they
> left an additional blank line in the above.

Hi Russell,

We kindly pinged you several times asking for your state and for the
PR, but I suppose you were just too busy. Your PR were kind of
blocking patches for sdhci, if you remember.

Anyway, we did get some folks to test the patches and was thus fairly
confident that we could merge them. Chris asked me to try to collect
them in a PR for him, so I did. Sorry if I managed to screw some
things up, there were several conflicts and actual regressions, which
I tried to take care of.

The mmc people were also very helping in sending patches to fixup
related regressions, immediately after we merged your patchset. Thus
together I think we managed to pull it off.

>
> The other thing I'd ask is that the MMC people learn C precedence
> rules, and realise that it's not necessary (and actively harmful)
> to add additional parenthesis around simple if() conditions.  Testing
> for timing being one of two values does not need anything more than
> one set of parenthesis - it does not need if ((a == b) || (a == c)) -
> if (a == b || a == c) does just fine, and is less confusing when
> encountering more complex statements, such as:
>
>         if ((((a == b) || (a == c)) && ((d > a) || (d < c))) || (z == f))
>
> compared with:
>
>         if (((a == b || a == c) && (d > a || d < c)) || z == f)
>
> With the former "style", I normally end up having to pull the file into
> the editor, and rewrite the damned statement to work out what the
> grouping is, because the excessive use of parenthesis is detrimental to
> readability.  Don't do it.  Learn the C precedence rules and keep code
> readable.

Sure, we will adopt.

Please, feel free to send a patch to fixup my misstake. I will happily apply it.

Kind regards
Ulf Hansson