* [PATCH v2] mmc: mediatek: add wait dma stop done flow
@ 2021-08-09 7:23 Derong Liu
2021-08-16 10:27 ` Ulf Hansson
0 siblings, 1 reply; 2+ messages in thread
From: Derong Liu @ 2021-08-09 7:23 UTC (permalink / raw)
To: Chaotian Jing, Ulf Hansson, Matthias Brugger
Cc: linux-mmc, linux-arm-kernel, linux-mediatek, linux-kernel,
wsp_upstream, Peng Zhou, Derong Liu
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.
Signed-off-by: Derong Liu <derong.liu@mediatek.com>
---
drivers/mmc/host/mtk-sd.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 4dfc246c5f95..1dfd2842471b 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -2339,6 +2339,8 @@ 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);
+ while (readl(host->base + MSDC_DMA_CFG) & MSDC_DMA_CFG_STS)
+ cpu_relax();
msdc_reset_hw(host);
}
}
--
2.18.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] mmc: mediatek: add wait dma stop done flow
2021-08-09 7:23 [PATCH v2] mmc: mediatek: add wait dma stop done flow Derong Liu
@ 2021-08-16 10:27 ` Ulf Hansson
0 siblings, 0 replies; 2+ messages in thread
From: Ulf Hansson @ 2021-08-16 10:27 UTC (permalink / raw)
To: Derong Liu
Cc: Chaotian Jing, Matthias Brugger, linux-mmc, Linux ARM,
moderated list:ARM/Mediatek SoC support,
Linux Kernel Mailing List, wsp_upstream, Peng Zhou
On Mon, 9 Aug 2021 at 09:25, Derong Liu <derong.liu@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.
>
> Signed-off-by: Derong Liu <derong.liu@mediatek.com>
> ---
> drivers/mmc/host/mtk-sd.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index 4dfc246c5f95..1dfd2842471b 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -2339,6 +2339,8 @@ 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);
> + while (readl(host->base + MSDC_DMA_CFG) & MSDC_DMA_CFG_STS)
> + cpu_relax();
I suggest you look into using readl_poll_timeout() - as we don't want
to hang indefinitely, no matter what.
> msdc_reset_hw(host);
> }
> }
> --
> 2.18.0
Kind regards
Uffe
^ permalink raw reply [flat|nested] 2+ messages in thread
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