[PATCH v3] mmc: mediatek: add wait dma stop done flow

[Ulf Hansson]

On Fri, 27 Aug 2021 at 09:15, Derong Liu <derong.liu at mediatek.com> wrote:
>
> We found this issue on a 5G platform, during CMDQ error handling, if DMA status is active when it call msdc_reset_hw, it means mmc host hw reset and DMA transfer will be parallel, mmc host may access sram region unexpectedly.
> According to the programming guide of mtk mmc host, it needs to wait for dma stop done after set dma stop.
> This change should be applied to all SoCs.
>
> Change-Id: I9b87523f19b24ca73958bbcb83bb418413c5a180

I am dropping this tag.

> Signed-off-by: Derong Liu <derong.liu at mediatek.com>

Applied for next, thanks! I guess we should also tag this for stable
kernels, right?

Kind regards
Uffe


> ---
>  drivers/mmc/host/mtk-sd.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index 4dfc246c5f95..b99330bad6a5 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -8,6 +8,7 @@
>  #include <linux/clk.h>
>  #include <linux/delay.h>
>  #include <linux/dma-mapping.h>
> +#include <linux/iopoll.h>
>  #include <linux/ioport.h>
>  #include <linux/irq.h>
>  #include <linux/of_address.h>
> @@ -2330,6 +2331,7 @@ static void msdc_cqe_enable(struct mmc_host *mmc)
>  static void msdc_cqe_disable(struct mmc_host *mmc, bool recovery)
>  {
>         struct msdc_host *host = mmc_priv(mmc);
> +       unsigned int val = 0;
>
>         /* disable cmdq irq */
>         sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INT_CMDQ);
> @@ -2339,6 +2341,9 @@ static void msdc_cqe_disable(struct mmc_host *mmc, bool recovery)
>         if (recovery) {
>                 sdr_set_field(host->base + MSDC_DMA_CTRL,
>                               MSDC_DMA_CTRL_STOP, 1);
> +               if (WARN_ON(readl_poll_timeout(host->base + MSDC_DMA_CFG, val,
> +                       !(val & MSDC_DMA_CFG_STS), 1, 3000)))
> +                       return;
>                 msdc_reset_hw(host);
>         }
>  }
> --
> 2.18.0