Re: [PATCH 2/3] mmc: sdhci_am654: Reset Command and Data line after tuning
From: Adrian Hunter
Date: Wed Jan 15 2020 - 08:13:17 EST
On 8/01/20 4:33 pm, Faiz Abbas wrote:
> The tuning data is leftover in the buffer after tuning. This can cause
> issues in future data commands, especially with CQHCI. Reset the command
> and data lines after tuning to continue from a clean state.
>
> Fixes: 41fd4caeb00b ("mmc: sdhci_am654: Add Initial Support for AM654 SDHCI driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci_am654.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci_am654.c b/drivers/mmc/host/sdhci_am654.c
> index 2d38b1e12a7e..59c0c41b3739 100644
> --- a/drivers/mmc/host/sdhci_am654.c
> +++ b/drivers/mmc/host/sdhci_am654.c
> @@ -240,6 +240,22 @@ static void sdhci_am654_write_b(struct sdhci_host *host, u8 val, int reg)
> writeb(val, host->ioaddr + reg);
> }
>
> +static int sdhci_am654_execute_tuning(struct mmc_host *mmc, u32 opcode)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + int err = sdhci_execute_tuning(mmc, opcode);
> +
> + if (err)
> + return err;
> + /*
> + * Tuning data remains in the buffer after tuning.
> + * Do a command and data reset to get rid of it
> + */
> + sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
> +
> + return 0;
> +}
> +
> static struct sdhci_ops sdhci_am654_ops = {
> .get_max_clock = sdhci_pltfm_clk_get_max_clock,
> .get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
> @@ -546,6 +562,8 @@ static int sdhci_am654_probe(struct platform_device *pdev)
> goto pm_runtime_put;
> }
>
> + host->mmc_host_ops.execute_tuning = sdhci_am654_execute_tuning;
> +
> ret = sdhci_am654_init(host);
> if (ret)
> goto pm_runtime_put;
>