RE: [PATCH v2 2/4] mmc: dw_mmc: fix the IDMAC sw reset

[Seungwon Jeon <tgih.jun@samsung.com>]

Dmitry Shmidt <dimitrysh@android.com>
> On Mon, May 21, 2012 at 9:01 PM, Seungwon Jeon <tgih.jun@samsung.com> wrote:
> > IDMAC may not be cleaned in driver probe if it has
> > been already used in boot time. So IDMAC needs sw
> > reset newly. And DMA interface reset precedes the
> > internal DMAC reset. Additionally SDMMC_IDMAC_SWRESET
> > is replaced with magic code.
> >
> > Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
> > ---
> >  drivers/mmc/host/dw_mmc.c |   24 ++++++++++++------------
> >  1 files changed, 12 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> > index b46faf0..98fe023 100644
> > --- a/drivers/mmc/host/dw_mmc.c
> > +++ b/drivers/mmc/host/dw_mmc.c
> > @@ -418,6 +418,8 @@ static int dw_mci_idmac_init(struct dw_mci *host)
> >        p->des3 = host->sg_dma;
> >        p->des0 = IDMAC_DES0_ER;
> >
> > +       mci_writel(host, BMOD, SDMMC_IDMAC_SWRESET);
> > +
> >        /* Mask out interrupts - get Tx & Rx complete only */
> >        mci_writel(host, IDINTEN, SDMMC_IDMAC_INT_NI | SDMMC_IDMAC_INT_RI |
> >                   SDMMC_IDMAC_INT_TI);
> > @@ -1724,7 +1726,8 @@ static void dw_mci_work_routine_card(struct work_struct *work)
> >
> >  #ifdef CONFIG_MMC_DW_IDMAC
> >                                ctrl = mci_readl(host, BMOD);
> > -                               ctrl |= 0x01; /* Software reset of DMA */
> > +                               /* Software reset of DMA */
> > +                               ctrl |= SDMMC_IDMAC_SWRESET;
> >                                mci_writel(host, BMOD, ctrl);
> >  #endif
> >
> > @@ -1949,10 +1952,6 @@ int dw_mci_probe(struct dw_mci *host)
> >        spin_lock_init(&host->lock);
> >        INIT_LIST_HEAD(&host->queue);
> >
> > -
> > -       host->dma_ops = host->pdata->dma_ops;
> > -       dw_mci_init_dma(host);
> > -
> >        /*
> >         * Get the host data width - this assumes that HCON has been set with
> >         * the correct values.
> > @@ -1980,10 +1979,11 @@ int dw_mci_probe(struct dw_mci *host)
> >        }
> >
> >        /* Reset all blocks */
> > -       if (!mci_wait_reset(&host->dev, host)) {
> > -               ret = -ENODEV;
> > -               goto err_dmaunmap;
> > -       }
> > +       if (!mci_wait_reset(&host->dev, host))
> > +               return -ENODEV;
> 
> You would probably want something like this:
> +       if (!mci_wait_reset(&host->dev, host)) {
> +               ret = -ENODEV;
> +               goto err_free_hclk;
> +       }
This is applicable to only our local branch.

> 
> > +
> > +       host->dma_ops = host->pdata->dma_ops;
> > +       dw_mci_init_dma(host);
> >
> >        /* Clear the interrupts for the host controller */
> >        mci_writel(host, RINTSTS, 0xFFFFFFFF);
> > @@ -2169,14 +2169,14 @@ int dw_mci_resume(struct dw_mci *host)
> >        if (host->vmmc)
> >                regulator_enable(host->vmmc);
> >
> > -       if (host->dma_ops->init)
> > -               host->dma_ops->init(host);
> > -
> >        if (!mci_wait_reset(&host->dev, host)) {
> >                ret = -ENODEV;
> >                return ret;
> >        }
> >
> > +       if (host->dma_ops->init)
> > +               host->dma_ops->init(host);
> > +
> >        /* Restore the old value at FIFOTH register */
> >        mci_writel(host, FIFOTH, host->fifoth_val);
> >
> > --
> > 1.7.0.4
> >
> >
> > --
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