On 30 January 2017 at 11:11, Ravikumar Kattekola <rk@xxxxxx> wrote:
> From: Kishon Vijay Abraham I <kishon@xxxxxx>
>
> commit e2bf08d643a244ccb ("omap_hsmmc: set a large data timeout for
> commands with busy signal") sets an arbitrary timeout value (100ms) for
> commands like CMD6 (MMC SWITCH). However extended CSD register defined
> in the eMMC standard has a field for GENERIC_CMD6_TIME which indicates
> the default maximum timeout for a SWITCH command.
> Use busy_timeout of cmd structure (populated with GENERIC_CMD6_TIME
> in the case of SWITCH command) to program the data timeout value in
> omap_hsmmc driver.
> SWITCH command to turn the cache on took more than 100ms to complete
> with MICRON eMMC card present in AM572x IDK REV 1.3A resulting in
> timeout and failed enumeration. It is fixed here by programming the
> timeout with the value advertised in GENERIC_CMD6_TIME.
>
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
> Signed-off-by: Ravikumar Kattekola <rk@xxxxxx>
> ---
> drivers/mmc/host/omap_hsmmc.c | 20 ++++++++++++++------
> 1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index 0ee5650..51ca3d7 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -1527,16 +1527,24 @@ static void omap_hsmmc_start_dma_transfer(struct omap_hsmmc_host *host)
> omap_hsmmc_prepare_data(struct omap_hsmmc_host *host, struct mmc_request *req)
> {
> int ret;
> + unsigned int timeout;
> +
> host->data = req->data;
>
> if (req->data == NULL) {
> OMAP_HSMMC_WRITE(host->base, BLK, 0);
> - /*
> - * Set an arbitrary 100ms data timeout for commands with
> - * busy signal.
> - */
> - if (req->cmd->flags & MMC_RSP_BUSY)
> - set_data_timeout(host, 100000000U, 0);
> + if (req->cmd->flags & MMC_RSP_BUSY) {
> + timeout = req->cmd->busy_timeout * NSEC_PER_MSEC;
> +
> + /*
> + * Set an arbitrary 100ms data timeout for commands with
> + * busy signal and no indication of busy_timeout.
> + */
> + if (!timeout)
This is a bug in the mmc core if this ever happen.
Therefore I am particularly interested to find out if this is really
needed or it's just playing safe?
> + timeout = 100000000U;
> +
> + set_data_timeout(host, timeout, 0);
> + }
> return 0;
> }
>
> --
> 1.9.1
>
Kind regards
Uffe
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