| Message ID | 1439282492-6274-1-git-send-email-21cnbao@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 11 August 2015 at 10:41, Barry Song <21cnbao@gmail.com> wrote: > From: Weijun Yang <york.yang@csr.com> > > 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!? Kind regards Uffe > > Signed-off-by: Weijun Yang <york.yang@csr.com> > Signed-off-by: Barry Song <Baohua.Song@csr.com> > --- > 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 > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2015-08-18 1:11 GMT+08:00 Ulf Hansson <ulf.hansson@linaro.org>: > On 11 August 2015 at 10:41, Barry Song <21cnbao@gmail.com> wrote: >> From: Weijun Yang <york.yang@csr.com> >> >> 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@csr.com> >> Signed-off-by: Barry Song <Baohua.Song@csr.com> >> --- >> 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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 20 August 2015 at 02:16, Barry Song <21cnbao@gmail.com> wrote: > 2015-08-18 1:11 GMT+08:00 Ulf Hansson <ulf.hansson@linaro.org>: >> On 11 August 2015 at 10:41, Barry Song <21cnbao@gmail.com> wrote: >>> From: Weijun Yang <york.yang@csr.com> >>> >>> 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. Another way is to always try doing the tuning for DDR50, but in case of errors just ignore them and print a debug/info message!? Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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: