+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 > > 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? -- Regards, Sachin. -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
 |