| Message ID | 1462346074-19113-1-git-send-email-jh80.chung@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
? 2016/5/4 15:14, Jaehoon Chung ??: > If vqmmc is used and failed to switch voltage, then retry to switch > voltage. MMC core is providing the retrying scheame. > > Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> > --- > drivers/mmc/host/dw_mmc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 9dd1bd3..28602cc 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios) > dev_dbg(&mmc->class_dev, > "Regulator set error %d - %s V\n", > ret, uhs & v18 ? "1.8" : "3.3"); > - return ret; > + return -EAGAIN; > } > } If not vqmmc is assigned, dw_mci_switch_voltage still returns success to mmc core? > mci_writel(host, UHS_REG, uhs); >
Hi Shawn, On 05/04/2016 07:41 PM, Shawn Lin wrote: > ? 2016/5/4 15:14, Jaehoon Chung ??: >> If vqmmc is used and failed to switch voltage, then retry to switch >> voltage. MMC core is providing the retrying scheame. >> >> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> >> --- >> drivers/mmc/host/dw_mmc.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >> index 9dd1bd3..28602cc 100644 >> --- a/drivers/mmc/host/dw_mmc.c >> +++ b/drivers/mmc/host/dw_mmc.c >> @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios) >> dev_dbg(&mmc->class_dev, >> "Regulator set error %d - %s V\n", >> ret, uhs & v18 ? "1.8" : "3.3"); >> - return ret; >> + return -EAGAIN; >> } >> } > > If not vqmmc is assigned, dw_mci_switch_voltage still returns success to > mmc core? There is comment in dw_mci_switch_voltage().. In some SoC, it's not harmful to switch voltage. But we can decide this condition whether try to set both or not. Best Regards, Jaehoon Chung > >> mci_writel(host, UHS_REG, uhs); >> > > -- 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 2016/5/10 9:55, Jaehoon Chung wrote: > Hi Shawn, > > On 05/04/2016 07:41 PM, Shawn Lin wrote: >> ? 2016/5/4 15:14, Jaehoon Chung ??: >>> If vqmmc is used and failed to switch voltage, then retry to switch >>> voltage. MMC core is providing the retrying scheame. >>> >>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> >>> --- >>> drivers/mmc/host/dw_mmc.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >>> index 9dd1bd3..28602cc 100644 >>> --- a/drivers/mmc/host/dw_mmc.c >>> +++ b/drivers/mmc/host/dw_mmc.c >>> @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios) >>> dev_dbg(&mmc->class_dev, >>> "Regulator set error %d - %s V\n", >>> ret, uhs & v18 ? "1.8" : "3.3"); >>> - return ret; >>> + return -EAGAIN; >>> } >>> } >> >> If not vqmmc is assigned, dw_mci_switch_voltage still returns success to >> mmc core? > > There is comment in dw_mci_switch_voltage().. In some SoC, it's not harmful to switch voltage. > But we can decide this condition whether try to set both or not. Because for dw_mmc-rockchip, we always need to swicth voltage by regulator. So do you mean some exynos Socs can switch voltage just by setting UHS_REG!? So to make things safe, we can set UHS_REG and switch voltage by regulator both? > > Best Regards, > Jaehoon Chung > >> >>> mci_writel(host, UHS_REG, uhs); >>> >> >> > > -- > 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 > -- 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 05/10/2016 06:24 PM, Shawn Lin wrote: > On 2016/5/10 9:55, Jaehoon Chung wrote: >> Hi Shawn, >> >> On 05/04/2016 07:41 PM, Shawn Lin wrote: >>> ? 2016/5/4 15:14, Jaehoon Chung ??: >>>> If vqmmc is used and failed to switch voltage, then retry to switch >>>> voltage. MMC core is providing the retrying scheame. >>>> >>>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> >>>> --- >>>> drivers/mmc/host/dw_mmc.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c >>>> index 9dd1bd3..28602cc 100644 >>>> --- a/drivers/mmc/host/dw_mmc.c >>>> +++ b/drivers/mmc/host/dw_mmc.c >>>> @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios) >>>> dev_dbg(&mmc->class_dev, >>>> "Regulator set error %d - %s V\n", >>>> ret, uhs & v18 ? "1.8" : "3.3"); >>>> - return ret; >>>> + return -EAGAIN; >>>> } >>>> } >>> >>> If not vqmmc is assigned, dw_mci_switch_voltage still returns success to >>> mmc core? >> >> There is comment in dw_mci_switch_voltage().. In some SoC, it's not harmful to switch voltage. >> But we can decide this condition whether try to set both or not. > > > Because for dw_mmc-rockchip, we always need to swicth voltage by > regulator. So do you mean some exynos Socs can switch voltage just > by setting UHS_REG!? So to make things safe, we can set UHS_REG and > switch voltage by regulator both? Ok. I will update the patch. Best Regards, Jaehoon Chung > > > >> >> Best Regards, >> Jaehoon Chung >> >>> >>>> mci_writel(host, UHS_REG, uhs); >>>> >>> >>> >> >> -- >> 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 >> > > -- > 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 > > -- 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/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 9dd1bd3..28602cc 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios) dev_dbg(&mmc->class_dev, "Regulator set error %d - %s V\n", ret, uhs & v18 ? "1.8" : "3.3"); - return ret; + return -EAGAIN; } } mci_writel(host, UHS_REG, uhs);
If vqmmc is used and failed to switch voltage, then retry to switch voltage. MMC core is providing the retrying scheame. Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com> --- drivers/mmc/host/dw_mmc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)