On Mon, 6 Jun 2022 at 16:21, Mengqi Zhang <mengqi.zhang@xxxxxxxxxxxx> wrote:
>
> MediaTek IP requires that after dma stop, it need to wait this dma stop
> bit auto-reset to 0. When bus is in high loading state, it will take a
> while for the dma stop complete. If there is no waiting operation here,
> when program runs to clear fifo and reset, bus will hang.
>
> In addition, there should be no return in msdc_data_xfer_next, because no
> matter what error occurs here, it should continue to excute to the
> following mmc_request_done. Otherwise the core layer may wait complete
> forever.
>
> Signed-off-by: Mengqi Zhang <mengqi.zhang@xxxxxxxxxxxx>
Is there a certain commit this fixes? In that case, we should add a fixes tag.
> ---
> drivers/mmc/host/mtk-sd.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
> index 195dc897188b..c925f45786c2 100644
> --- a/drivers/mmc/host/mtk-sd.c
> +++ b/drivers/mmc/host/mtk-sd.c
> @@ -1385,12 +1385,15 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
> sdr_set_field(host->base + MSDC_DMA_CTRL, MSDC_DMA_CTRL_STOP,
> 1);
>
> + ret = readl_poll_timeout_atomic(host->base + MSDC_DMA_CTRL, val,
> + !(val & MSDC_DMA_CTRL_STOP), 1, 20000);
> + if (ret)
> + dev_dbg(host->dev, "DMA stop timed out\n");
> +
> ret = readl_poll_timeout_atomic(host->base + MSDC_DMA_CFG, val,
> !(val & MSDC_DMA_CFG_STS), 1, 20000);
> - if (ret) {
> - dev_dbg(host->dev, "DMA stop timed out\n");
> - return false;
Looks like msdc_data_xfer_done() should be turned into a void
function, as it would always return true beyond this change.
> - }
> + if (ret)
> + dev_dbg(host->dev, "DMA inactive timed out\n");
>
> sdr_clr_bits(host->base + MSDC_INTEN, data_ints_mask);
> dev_dbg(host->dev, "DMA stop\n");
> @@ -2416,6 +2419,9 @@ 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_CTRL, val,
> + !(val & MSDC_DMA_CTRL_STOP), 1, 3000)))
> + return;
> if (WARN_ON(readl_poll_timeout(host->base + MSDC_DMA_CFG, val,
> !(val & MSDC_DMA_CFG_STS), 1, 3000)))
> return;
Kind regards
Uffe
