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

From: Ulf Hansson
Date: Mon Sep 06 2021 - 13:10:37 EST


On Fri, 27 Aug 2021 at 09:15, Derong Liu <derong.liu@xxxxxxxxxxxx> 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@xxxxxxxxxxxx>

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