On 8 October 2014 02:19, Jaehoon Chung <jh80.chung@xxxxxxxxxxx> wrote: > Hi, > > On 10/07/2014 01:51 AM, Doug Anderson wrote: >> Bartlomiej, >> >> On Thu, Oct 2, 2014 at 10:24 AM, Bartlomiej Zolnierkiewicz >> <b.zolnierkie@xxxxxxxxxxx> wrote: >>> >>> Hi, >>> >>> On Thursday, October 02, 2014 09:45:41 AM Doug Anderson wrote: >>>> Bartiomiej >>>> >>>> On Thu, Oct 2, 2014 at 9:39 AM, Bartlomiej Zolnierkiewicz >>>> <b.zolnierkie@xxxxxxxxxxx> wrote: >>>>> On Thursday, October 02, 2014 09:19:08 AM Doug Anderson wrote: >>>>>> Bartiomiej, >>>>>> >>>>>> On Thu, Oct 2, 2014 at 9:10 AM, Bartlomiej Zolnierkiewicz >>>>>> <b.zolnierkie@xxxxxxxxxxx> wrote: >>>>>>> Regulators for MMC2 (SD card) are PVDD_TFLASH_2V8 (LDO19) for vmmc >>>>>>> and PVDD_APIO_MMCOFF_2V8 (LDO13) for vqmmc. Currently the device >>>>>>> tree entry for MMC2 uses PVDD_PRE_1V8 (LDO10) for vmmc and vqmmc is >>>>>>> not specified. Fix it. >>>>>>> >>>>>>> Without this patch: >>>>>>> - "mmc: dw_mmc: use mmc_regulator_get_supply to handle regulators" >>>>>>> patch causes a SD card detection to fail >>>>>>> - "mmc: dw_mmc: Support voltage changes" patch causes a boot hang >>>>>>> >>>>>>> This patch fixes both above problems. >>>>>>> >>>>>>> Suggested-by: Doug Anderson <dianders@xxxxxxxxxx> >>>>>>> Cc: Yuvaraj Kumar C D <yuvaraj.cd@xxxxxxxxxxx> >>>>>>> Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx> >>>>>>> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> >>>>>>> Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> >>>>>>> --- >>>>>>> arch/arm/boot/dts/exynos5420-arndale-octa.dts | 3 ++- >>>>>>> 1 file changed, 2 insertions(+), 1 deletion(-) >>>>>>> >>>>>>> Index: b/arch/arm/boot/dts/exynos5420-arndale-octa.dts >>>>>>> =================================================================== >>>>>>> --- a/arch/arm/boot/dts/exynos5420-arndale-octa.dts 2014-10-02 15:44:53.014826886 +0200 >>>>>>> +++ b/arch/arm/boot/dts/exynos5420-arndale-octa.dts 2014-10-02 17:35:24.110600398 +0200 >>>>>>> @@ -74,7 +74,8 @@ >>>>>>> samsung,dw-mshc-ddr-timing = <1 2>; >>>>>>> pinctrl-names = "default"; >>>>>>> pinctrl-0 = <&sd2_clk &sd2_cmd &sd2_cd &sd2_bus4>; >>>>>>> - vmmc-supply = <&ldo10_reg>; >>>>>>> + vmmc-supply = <&ldo19_reg>; >>>>>>> + vqmmc-supply = <&ldo13_reg>; >>>>>> >>>>>> This looks right to me. ...but I notice that ldo13 and ldo19 are not >>>>>> "always-on" in the DTS. Are you sure card detect works for you if you >>>>>> eject your card and try to put it back in? >>>>>> >>>>>> ...eventually the "always-on" won't be needed, but for now I think it is... >>>>> >>>>> Card detection works fine without "always-on". >>>> >>>> That's weird. >>>> >>>> 1. In the schematics I see XMMC2CDN has an external pullup to PVDD_TFLASH_2V8. >>>> >>>> 2. The internal pullup should (I think) be to VDDQ_MMC2 which is >>>> PVDD_APIO_MMCOFF_2V8. >>>> >>>> 3. In (51da224 mmc: dw_mmc: use mmc_regulator_get_supply to handle >>>> regulators) we should be turning off both regulators in >>>> "MMC_POWER_OFF". >>>> >>>> 4. If I understand correctly MMC_POWER_OFF is called when the card is >>>> ejected, which means that both regulators should be off when the card >>>> is ejected. >>>> >>>> 5. I don't think card detect can work if neither regulator is powered. >>>> >>>> >>>> One of the above points must be wrong. Any idea which one? Can you >>>> check to see if MMC_POWER_OFF is called for you when the card is >>>> ejected? Can you check to see if these regulators are off? >>> >>> MMC_POWER_OFF is called on card removal and both regulators get disabled >>> (I have verified that they are really off with regulator_is_enabled() which >>> returns 1 before and 0 after disabling regulator). It seems that 5. is >>> wrong? >> >> This really doesn't make a lot of sense to me, so I'm still kinda >> confused. If you want to call it good then that's your (and Ulf's) >> decision, but it's the kind of thing that would keep me up at night. >> How can this pin be high if all the regulators pulling it up are off? >> Is there a current leak somewhere and that's why it's working? >> >> How this is supposed to work (as I understand it): >> >> 1. When no card is inserted then this pin is supposed to be pulled up >> to VDDQ_MMC2. That could be either an internal or an external pullup. >> It should be pulled up to VDDQ_MMC2 (as opposed to any other voltage) >> since the exynos manual documents that this pin lives in the VDDQ_MMC2 >> io domain. Note that it could be pulled up externally to a different >> supply than the one going to VDDQ_MMC2, but for correctness it should >> be the same voltage. >> >> 2. When a card is inserted, the pin will be grounded (AKA this is an >> open drain pin). >> >> >> With your patch, can you probe the pin and see if card detect is high >> when all the regulators are off? Any idea how it gets high? If you >> turn off the internal pullup is it still high? > > I remembered that I and Doug were discussed for this problem with exynos5420-peach board(?), right? > Is arndale-octa board the same circuit with peach? > If it's same, I think Doug's comment is right. > But if card-detect pis is used with other power, we don't need to consider the VDDQ_MMC2 power domain. > It needs more information and checks its schematic. May I suggest we go ahead and apply this patch to fix the problems for Arndale Octa!? I am soon about to send the PR for 3.18. We should then follow up on this discussion and sort out why/how it actually works. So, I need an ack from some of the ARM SOC maintainers. I have looped in Arnd Bergmann, if Kukjin is busy. Kind regards Uffe -- 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
