Re: [PATCH] mmc: Test bus-width for old MMC devices (v2)

zhangfei gao
2010-12-28T08:27:42Z

On Wed, Dec 22, 2010 at 3:59 AM, Takashi Iwai <tiwai@suse.de> wrote:
> At Tue, 21 Dec 2010 22:56:32 -0500,
> zhangfei gao wrote:
>>
>> On Tue, Dec 21, 2010 at 11:36 AM, Philip Rakity <prakity@marvell.com> wrote:
>> >
>> >
>> > Can you please try this diff and see if it works for you.
>> >
>> > Will do formal patch after your testing.  What card is failing ?
>> >
>> > Please let me know the manufacturing information so can add card to my test suite.
>> >
>> > Philip
>> >
>> > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>> > index 1d8409f..77072c8 100644
>> > --- a/drivers/mmc/core/mmc.c
>> > +++ b/drivers/mmc/core/mmc.c
>> > @@ -558,6 +558,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>> >                                         EXT_CSD_BUS_WIDTH,
>> >                                         ext_csd_bits[idx][0]);
>> >                        if (!err) {
>> > +                               mmc_set_bus_width_ddr(card->host,
>> > +                                                     bus_width, MMC_SDR_MODE);
>> Test OK,
>> Curious why move here, then mmc_set_bus_width_ddr is called twice in
>> fact when ddr=0 &&  (!(host->caps & MMC_CAP_BUS_WIDTH_TEST)), though
>> not impact function.
>> mmc_set_bus_width is mmc_set_bus_width_ddr(host, width, MMC_SDR_MODE).
>
> Right.  How about the patch below?  This one just moves the call
> before caps test, so it's simpler (and avoiding double calls).
>
>
> thanks,
>
> Takashi
>
> ===
> From b66b9704f8d2fefa402741fb17949224b2766b4f Mon Sep 17 00:00:00 2001
> From: Takashi Iwai <tiwai@suse.de>
> Date: Wed, 22 Dec 2010 09:54:33 +0100
> Subject: [PATCH] mmc: fix mmc_set_bus_width_ddr() call without bus-width-test cap
>
> With the bus-width test patch, mmc_set_bus_width*() isn't called properly
> when the driver doesn't set MMC_CAP_BUS_WIDTH and no DDR mode.
> This patch fixes the regression by moving the call up before the cap test.
>
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---
>  drivers/mmc/core/mmc.c |    4 ++--
>  1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 1d8409f..c86dd73 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -558,6 +558,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>                                         EXT_CSD_BUS_WIDTH,
>                                         ext_csd_bits[idx][0]);
>                        if (!err) {
> +                               mmc_set_bus_width_ddr(card->host,
> +                                                     bus_width, MMC_SDR_MODE);
>                                /*
>                                 * If controller can't handle bus width test,
>                                 * use the highest bus width to maintain
> @@ -565,8 +567,6 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>                                 */
>                                if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST))
>                                        break;
> -                               mmc_set_bus_width_ddr(card->host,
> -                                                     bus_width, MMC_SDR_MODE);
>                                err = mmc_bus_test(card, bus_width);
>                                if (!err)
>                                        break;
> --
> 1.7.3.4

It's also works, solve (ddr=0 & (!(host->caps & MMC_CAP_BUS_WIDTH_TEST))) issue.
Is it possible to merge to original patch.

Thanks
>
>
>