On Mon, 27 Jan 2025 at 23:41, Erick Shepherd <erick.shepherd@xxxxxx> wrote:
>
> Add a new field to the mmc_host struct to track when the card should
> skip the initial tuning and use it to conditionally stop tuning in the
> mmc_sd_init_uhs_card function. Currently the new field only gets set
> when a DDR50 card fails to tune, which indicates the card does not
> support tuning.
>
> Signed-off-by: Erick Shepherd <erick.shepherd@xxxxxx>
> ---
> drivers/mmc/core/sd.c | 4 +++-
> include/linux/mmc/host.h | 1 +
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index cc757b850e79..353715fd8f53 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -663,7 +663,8 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
> if (!mmc_host_is_spi(card->host) &&
> (card->host->ios.timing == MMC_TIMING_UHS_SDR50 ||
> card->host->ios.timing == MMC_TIMING_UHS_DDR50 ||
> - card->host->ios.timing == MMC_TIMING_UHS_SDR104)) {
> + card->host->ios.timing == MMC_TIMING_UHS_SDR104) &&
> + !card->host->skip_init_tune) {
> err = mmc_execute_tuning(card);
>
> /*
> @@ -676,6 +677,7 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
> if (err && card->host->ios.timing == MMC_TIMING_UHS_DDR50) {
> pr_warn("%s: ddr50 tuning failed\n",
> mmc_hostname(card->host));
> + card->host->skip_init_tune = 1;
Rather than adding a host specific flag to let the core signal to the
host driver that it should skip tuning, I think it would be better if
we can avoid the core to request a tuning instead.
So we need to get the information from the host, during the first
tuning attempt if it fails and then the tuning should be disabled for
the *card*, forever.
> err = 0;
> }
> }
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 68f09a955a90..91c4db6837c9 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -486,6 +486,7 @@ struct mmc_host {
> unsigned int use_spi_crc:1;
> unsigned int claimed:1; /* host exclusively claimed */
> unsigned int doing_init_tune:1; /* initial tuning in progress */
> + unsigned int skip_init_tune:1; /* skip the initial tuning */
> unsigned int can_retune:1; /* re-tuning can be used */
> unsigned int doing_retune:1; /* re-tuning in progress */
> unsigned int retune_now:1; /* do re-tuning at next req */
> --
> 2.43.0
>
Again, please re-submit and loop in Adrian to get his opinion on this.
Kind regards
Uffe
