On Tue, Apr 14, 2020 at 06:13:59PM +0200, Ulf Hansson wrote:
> Some commands uses R1B responses, which means the card may assert the DAT0
> line to signal busy for a period of time, after it has received the
> command. The mmc core normally specifies the busy period for the command in
> the cmd->busy_timeout. Ideally the driver should respect it, but that
> requires quite some update of the code, so let's defer that to someone with
> the HW at hand.
>
> Instead, let's inform the mmc core about the maximum supported busy timeout
> in ->max_busy_timeout during ->probe(). This value corresponds to the fixed
> 4s timeout used by usdhi6rol0. In this way, we let the mmc core validate
> the needed timeout, which may lead to that it converts from a R1B into a R1
> response and then use CMD13 to poll for busy completion.
>
> In other words, this change enables support for commands with longer busy
> periods than 4s, like erase (CMD38) for example.
Acked-by: Jesper Nilsson <jesper.nilsson@xxxxxxxx>
> Cc: Lars Persson <lars.persson@xxxxxxxx>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
> drivers/mmc/host/usdhi6rol0.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/usdhi6rol0.c b/drivers/mmc/host/usdhi6rol0.c
> index 9a0b1e4e405d..369b8dee2e3d 100644
> --- a/drivers/mmc/host/usdhi6rol0.c
> +++ b/drivers/mmc/host/usdhi6rol0.c
> @@ -136,6 +136,8 @@
>
> #define USDHI6_MIN_DMA 64
>
> +#define USDHI6_REQ_TIMEOUT_MS 4000
> +
> enum usdhi6_wait_for {
> USDHI6_WAIT_FOR_REQUEST,
> USDHI6_WAIT_FOR_CMD,
> @@ -1763,7 +1765,12 @@ static int usdhi6_probe(struct platform_device *pdev)
> host = mmc_priv(mmc);
> host->mmc = mmc;
> host->wait = USDHI6_WAIT_FOR_REQUEST;
> - host->timeout = msecs_to_jiffies(4000);
> + host->timeout = msecs_to_jiffies(USDHI6_REQ_TIMEOUT_MS);
> + /*
> + * We use a fixed timeout of 4s, hence inform the core about it. A
> + * future improvement should instead respect the cmd->busy_timeout.
> + */
> + mmc->max_busy_timeout = USDHI6_REQ_TIMEOUT_MS;
>
> host->pinctrl = devm_pinctrl_get(&pdev->dev);
> if (IS_ERR(host->pinctrl)) {
> --
> 2.20.1
>
/^JN - Jesper Nilsson
--
Jesper Nilsson -- jesper.nilsson@xxxxxxxx
