Re: [PATCH] mmc: sdhci: correct the tuning command handle for PIO mode

[Ulf Hansson <ulf.hansson@linaro.org>]

On Fri, 13 Aug 2021 at 14:55, <haibo.chen@nxp.com> wrote:
>
> From: Haibo Chen <haibo.chen@nxp.com>
>
> If sdhci use PIO mode, and use mmc_send_tuning() to send the
> tuning command, system will stuck because of the storm irq
> of sdhci. For PIO mode, use mmc_send_tuning(), it will trigger
> buffer_read_ready interrupt and data transfer complete interrupt.
> In current code logic, it will directly return in sdhci_data_irq,
> can not call the sdhci_transfer_pio(). So the buffer_read_ready
> interrupt storm happen. So for standard tuning method, need to
> excluse this case.
>
> Signed-off-by: Haibo Chen <haibo.chen@nxp.com>

Applied for next (and by dropping parenthesis according to the comment
from Adrian), thanks!

Kind regards
Uffe



> ---
>  drivers/mmc/host/sdhci.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index aba6e10b8605..acee54b368b0 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3278,8 +3278,14 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>  {
>         u32 command;
>
> -       /* CMD19 generates _only_ Buffer Read Ready interrupt */
> -       if (intmask & SDHCI_INT_DATA_AVAIL) {
> +       /*
> +        * CMD19 generates _only_ Buffer Read Ready interrupt if
> +        * use sdhci_send_tuning.
> +        * Need to exclude this case: PIO mode and use mmc_send_tuning,
> +        * If not, sdhci_transfer_pio will never be called, make the
> +        * SDHCI_INT_DATA_AVAIL always there, stuck in irq storm.
> +        */
> +       if ((intmask & SDHCI_INT_DATA_AVAIL) && (!host->data)) {
>                 command = SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND));
>                 if (command == MMC_SEND_TUNING_BLOCK ||
>                     command == MMC_SEND_TUNING_BLOCK_HS200) {
> --
> 2.17.1
>