2015-08-18 1:11 GMT+08:00 Ulf Hansson <ulf.hansson@xxxxxxxxxx>: > On 11 August 2015 at 10:41, Barry Song <21cnbao@xxxxxxxxx> wrote: >> From: Weijun Yang <york.yang@xxxxxxx> >> >> As SD Specifications Part1 Physical Layer Specification Version >> 3.01 says, CMD19 tuning is available for unlocked cards in transfer >> state of 1.8V signaling mode. The small difference between v3.00 >> and 3.01 spec means that CMD19 tuning is also available for DDR50 >> mode. > > So what happens with cards following the 3.0 spec version, those > doesn't need to support the tuning CMD right? Perhaps that needs to be > addressed in this patch well!? from HW registers of the card, we cann't know whether the HW needs tuning. it is said 3.0.x need tuning, but 3.0 doesn't need. @weijun, pls fix me if i am wrong. if so, it seems we need a static flag somewhere to indicate whether the tuning is needed. we can't detect to find the tuning requirement. > > Kind regards > Uffe > >> >> Signed-off-by: Weijun Yang <york.yang@xxxxxxx> >> Signed-off-by: Barry Song <Baohua.Song@xxxxxxx> >> --- >> drivers/mmc/core/sd.c | 1 + >> drivers/mmc/host/sdhci.c | 1 + >> 2 files changed, 2 insertions(+) >> >> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c >> index 4e7366a..a1ed24d 100644 >> --- a/drivers/mmc/core/sd.c >> +++ b/drivers/mmc/core/sd.c >> @@ -629,6 +629,7 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card) >> */ >> if (!mmc_host_is_spi(card->host) && >> (card->sd_bus_speed == UHS_SDR50_BUS_SPEED || >> + card->sd_bus_speed == UHS_DDR50_BUS_SPEED || >> card->sd_bus_speed == UHS_SDR104_BUS_SPEED)) >> err = mmc_execute_tuning(card); >> out: >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >> index 1dbe932..812c19b 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -1891,6 +1891,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode) >> break; >> >> case MMC_TIMING_UHS_SDR104: >> + case MMC_TIMING_UHS_DDR50: >> break; >> >> case MMC_TIMING_UHS_SDR50: >> -- >> 1.9.1 >> -barry -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
