RE: [PATCH v1 1/1] mmc: core: hs200 fixes

["Subhash Jadavani" <subhashj@codeaurora.org>]

Hi Girish,

> -----Original Message-----
> From: linux-arm-msm-owner@vger.kernel.org [mailto:linux-arm-msm-
> owner@vger.kernel.org] On Behalf Of Girish K S
> Sent: Tuesday, March 06, 2012 3:30 PM
> To: Subhash Jadavani
> Cc: linux-mmc@vger.kernel.org; linux-arm-msm@vger.kernel.org;
> cjb@laptop.org
> Subject: Re: [PATCH v1 1/1] mmc: core: hs200 fixes
> 
> On 6 March 2012 12:54, Subhash Jadavani <subhashj@codeaurora.org>
> wrote:
> > This patch fixes following issues when HS200 is enabled:
> >
> > 1. If executing_tuning() host ops is called without
> > mmc_host_clk_hold(),
> >   card clocks might get turned off (if MMC_CLK_GATING is enabled)
> >   while execute_tuning() is in progress. So this patch makes sure
> >   that execute_tuning() is called with mmc_host_clk_hold().
> >
> > 2. If host timing mode is set to HS200 mode, there should not be
> >   any communication with the card until execute_tuning() is completed.
> >   But there is a chance that CMD6 might be sent to enable set HPI_EN
> >   (of HPI_MGMT field in EXT_CSD) before execute_tuning() is called.
> >   So this patch moves this operation after execute_tuning() is
completed.
> >
> > Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
> > ---
> >  drivers/mmc/core/mmc.c |   37 ++++++++++++++++++++-----------------
> >  1 files changed, 20 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index
> > a480663..08574ae 100644
> > --- a/drivers/mmc/core/mmc.c
> > +++ b/drivers/mmc/core/mmc.c
> > @@ -1030,22 +1030,6 @@ static int mmc_init_card(struct mmc_host *host,
> > u32 ocr,
> >        }
> >
> >        /*
> > -        * Enable HPI feature (if supported)
> > -        */
> > -       if (card->ext_csd.hpi) {
> > -               err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> > -                       EXT_CSD_HPI_MGMT, 1, 0);
> > -               if (err && err != -EBADMSG)
> > -                       goto free_card;
> > -               if (err) {
> > -                       pr_warning("%s: Enabling HPI failed\n",
> > -                                  mmc_hostname(card->host));
> > -                       err = 0;
> > -               } else
> > -                       card->ext_csd.hpi_en = 1;
> > -       }
> > -
> > -       /*
> >         * Compute bus speed.
> >         */
> >        max_dtr = (unsigned int)-1;
> > @@ -1094,9 +1078,12 @@ static int mmc_init_card(struct mmc_host *host,
> > u32 ocr,
> >                 * 4. execute tuning for HS200
> >                 */
> >                if ((host->caps2 & MMC_CAP2_HS200) &&
> > -                   card->host->ops->execute_tuning)
> > +                   card->host->ops->execute_tuning) {
> > +                       mmc_host_clk_hold(card->host);
> >                        err =
> > card->host->ops->execute_tuning(card->host,
> >                                MMC_SEND_TUNING_BLOCK_HS200);
> > +                       mmc_host_clk_release(card->host);
> > +               }
> >                if (err) {
> >                        pr_warning("%s: tuning execution failed\n",
> >                                   mmc_hostname(card->host)); @@
> > -1216,6 +1203,22 @@ static int mmc_init_card(struct mmc_host *host,
> > u32 ocr,
> >        }
> >
> >        /*
> > +        * Enable HPI feature (if supported)
> > +        */
> > +       if (card->ext_csd.hpi) {
> > +               err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
> > +                       EXT_CSD_HPI_MGMT, 1, 0);

> i think timeout value should be generic timeout value. Rest all looks
fine.

This is not introduced in this patch as I just moved this mmc_switch() as it
is. Do you still want me to fix this timeout value as part of this patch?

> > +               if (err && err != -EBADMSG)
> > +                       goto free_card;
> > +               if (err) {
> > +                       pr_warning("%s: Enabling HPI failed\n",
> > +                                  mmc_hostname(card->host));
> > +                       err = 0;
> > +               } else
> > +                       card->ext_csd.hpi_en = 1;
> > +       }
> > +
> > +       /*
> >         * If cache size is higher than 0, this indicates
> >         * the existence of cache and it can be turned on.
> >         */
> > --
> > 1.7.1.1
> >
> > --
> > Sent by a consultant of the Qualcomm Innovation Center, Inc.
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
> Forum.
> >
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