On 06/19/2014 07:40 PM, Sachin Kamat wrote: > On Thu, Jun 19, 2014 at 2:40 PM, Tim Kryger <tim.kryger@xxxxxxxxx> wrote: >> On Thu, Jun 19, 2014 at 1:49 AM, Sachin Kamat <spk.linux@xxxxxxxxx> wrote: >>> +cc Some relevant guys from Samsung >>> >>> On Thu, Jun 19, 2014 at 2:12 PM, Tim Kryger <tim.kryger@xxxxxxxxx> wrote: >>>> On Wed, Jun 18, 2014 at 8:54 PM, Sachin Kamat <spk.linux@xxxxxxxxx> wrote: >>>> >>>>>> On Wed, Jun 18, 2014 at 4:33 AM, Sachin Kamat <spk.linux@xxxxxxxxx> wrote: >>>> >>>>>>> I see the below error on Exynos4210 based Origen board with linux-next >>>>>>> (20140618). >>>>>>> Reverting the below commit works fine. >>>>>>> >>>>>>> Commit: 8d02e775a6 "mmc: sdhci: Use mmc core regulator infrastucture" >>>> >>>>>>> >>>>>>> -- [ 2.068992] sdhci: Secure Digital Host Controller Interface driver >>>>>>> [ 2.075059] sdhci: Copyright(c) Pierre Ossman >>>>>>> [ 2.079762] of_get_named_gpiod_flags: can't parse gpios property of >>>>>>> node '/sdhci@12510000[0]' >>>>>>> [ 2.088021] s3c-sdhci 12510000.sdhci: clock source 2: mmc_busclk.2 >>>>>>> (50000000 Hz) >>>>>>> [ 2.095322] of_get_named_gpiod_flags: can't parse gpios property of >>>>>>> node '/sdhci@12510000[0]' >>>>>>> [ 2.103794] of_get_named_gpiod_flags: can't parse gpios property of >>>>>>> node '/sdhci@12510000[0]' >>>>>>> [ 2.112478] s3c-sdhci 12510000.sdhci: No vqmmc regulator found >>>>>>> [ 2.118117] mmc0: Hardware doesn't report any support voltages. >>>>>>> [ 2.124004] s3c-sdhci 12510000.sdhci: sdhci_add_host() failed >>>>>>> [ 2.130080] of_get_named_gpiod_flags: can't parse gpios property of >>>>>>> node '/sdhci@12530000[0]' >>>>>>> [ 2.138352] s3c-sdhci 12530000.sdhci: clock source 2: mmc_busclk.2 >>>>>>> (16666667 Hz) >>>>>>> [ 2.145661] of_get_named_gpiod_flags: can't parse gpios property of >>>>>>> node '/sdhci@12530000[0]' >>>>>>> [ 2.154139] of_get_named_gpiod_flags: can't parse gpios property of >>>>>>> node '/sdhci@12530000[0]' >>>>>>> [ 2.162834] s3c-sdhci 12530000.sdhci: No vqmmc regulator found >>>>>>> [ 2.168464] mmc0: Hardware doesn't report any support voltages. >>>>>>> [ 2.174349] s3c-sdhci 12530000.sdhci: sdhci_add_host() failed >>>> >>>>>>> [ 2.336148] Waiting for root device /dev/mmcblk0p1... >>>> >>>>> FYI, the board has a 2.8V fixed regulator supply connected to the MMC. >>>>> You may refer to arch/arm/boot/dts/exynos4210-origen.dts for more details. >>>> >>>> A 2.8v regulator results in mmc->ocr_avail being set to MMC_VDD_27_28 >>>> | MMC_VDD_28_29. >>>> >>>> The SDHCI capabilities register only indicates support of three voltage levels >>>> - 1.8v: SDHCI_CAN_VDD_180 => MMC_VDD_165_195 >>>> - 3.0v: SDHCI_CAN_VDD_300 => MMC_VDD_29_30 | MMC_VDD_30_31 >>>> - 3.3v: SDHCI_CAN_VDD_330 => MMC_VDD_32_33 | MMC_VDD_33_34 Right. sdhci capabilities only indicated them. But I think SoC can be support the specific VDD range. >>>> >>>> Even if all capability bits of the host controller were set, there >>>> still wouldn't be any overlap. Thus you see a "Hardware doesn't >>>> report any support voltages" message. >>>> >>>> Previously, this issue was being swept under the rug by cec2e21 mmc: >>>> sdhci: Use regulator min/max voltage range according to spec. That >>>> change hacked up the voltage range checks such that with your 2.8v >>>> fixed regulator, the driver would believe the host could support >>>> MMC_VDD_29_30 | MMC_VDD_30_31 | MMC_VDD_32_33 | MMC_VDD_33_34. The >>>> driver would start down the path of commanding 3.3v-3.4v (the highest >>>> voltage range believed to be supported). At the last second, the >>>> driver would see the regulator was fixed and blindly skip over the set >>>> voltage operation, saving it from failure. >>>> >>>> Since my patch eliminates the bogus voltage range checks, your board >>>> is now getting caught playing too loose with the SDHCI regulator >>>> voltages. >>>> >>>> Furthermore, the fixed regulator special-case logic that helped hide >>>> your issue should also be considered for removal given that fixed >>>> regulators now behave properly thanks to c00dc35 regulator: core: >>>> Allow regulator_set_voltage for fixed regulators. >>> >>> Thanks for the detailed explanation. What do you propose to get this fixed? >> >> I'm not really sure of the best path forward. I suppose you could >> modify your device tree to lie about the voltage of the fixed >> regulator. Changing it to 3.0v should allow it to boot up but that is >> definitely a hack. I don't want to change the 3.0V at dt file...is it hack? i don't think so. Almost exynos4 Series is used the fixed regulator(2.8V). I didn't know exactly why we used the 2.8V. But i guess there is some reason.(H/W design). If we need to change ocr value, then i will add the quirk or controlling function for exynos into sdhci-s3c.c How about? > > Or I could simply remove the vmmc-supply property altogether (as it is optional) > and get the board to work. Then is it supported the power "always-on"? > >> It would be nice if the driver could be extended >> to handle the peculiarities of your board in a deliberate manner but >> limiting the common sdhci driver to supporting only the three voltages >> from the spec also seems sensible. > > Until such time that the driver gets fixed to handle 2.8V fixed supply your > current patch leaves several of Exynos boards broken for now. the all of exynos used the fixed-regulator(2.8v) should be broken. (Maybe exynos4 series??) > -- 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
