On Wed, Sep 30, 2015 at 4:07 PM, Heiko Stuebner <heiko at sntech.de> wrote: > From: Douglas Anderson <dianders at chromium.org> > > We've introduced a new helper in the MMC core: > mmc_regulator_set_vqmmc(). Let's use this in dw_mmc. Using this new > helper has some advantages: > > 1. We get the mmc_regulator_set_vqmmc() behavior of trying to match > VQMMC and VMMC when the signal voltage is 3.3V. This ensures max > compatibility. > > 2. We get rid of a few more warnings when probing unsupported > voltages. > > 3. We get rid of some non-dw_mmc specific code in dw_mmc. > > Signed-off-by: Douglas Anderson <dianders at chromium.org> > Signed-off-by: Heiko Stuebner <heiko at sntech.de> kernelci.org found a new failure in linux-next on exynos5800-peach-pi[1] and it was bisected down to this patch, which has hit linux-next in the form of commit fba2e23128d0 (mmc: dw_mmc: Use mmc_regulator_set_vqmmc in start_signal_voltage_switch). Based on a quick glance at the boot log[2], it looks to be a bad pointer dereference in regulator_get_voltage(). I confirmed that reverting this patch on top of next-20151009 gets my peach-pi booting again. Note that the boot failure is only on exynos_defconfig, not multi_v7_defconfig. Kevin [1] http://kernelci.org/boot/exynos5800-peach-pi/job/next/kernel/next-20151009/defconfig/exynos_defconfig/lab/lab-khilman/?_id=56177d3659b514a50c6c3267 [2] http://storage.kernelci.org/next/next-20151009/arm-exynos_defconfig/lab-khilman/boot-exynos5800-peach-pi.html > --- > drivers/mmc/host/dw_mmc.c | 17 ++++++----------- > 1 file changed, 6 insertions(+), 11 deletions(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index fcbf552..b1b7e7f 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -1279,7 +1279,6 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios) > const struct dw_mci_drv_data *drv_data = host->drv_data; > u32 uhs; > u32 v18 = SDMMC_UHS_18V << slot->id; > - int min_uv, max_uv; > int ret; > > if (drv_data && drv_data->switch_voltage) > @@ -1291,22 +1290,18 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios) > * does no harm but you need to set the regulator directly. Try both. > */ > uhs = mci_readl(host, UHS_REG); > - if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) { > - min_uv = 2700000; > - max_uv = 3600000; > + if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) > uhs &= ~v18; > - } else { > - min_uv = 1700000; > - max_uv = 1950000; > + else > uhs |= v18; > - } > + > if (!IS_ERR(mmc->supply.vqmmc)) { > - ret = regulator_set_voltage(mmc->supply.vqmmc, min_uv, max_uv); > + ret = mmc_regulator_set_vqmmc(mmc, ios); > > if (ret) { > dev_dbg(&mmc->class_dev, > - "Regulator set error %d: %d - %d\n", > - ret, min_uv, max_uv); > + "Regulator set error %d - %s V\n", > + ret, uhs & v18 ? "1.8" : "3.3"); > return ret; > } > } > -- > 2.5.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel at lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
