Hi Shashidhar, ok, now that the bus width switch error became fatal in recent kernels, the problem started to became painful... I added some debug printks to the mmc_switch function in mmc_ops.c: [ 1.433253] sdhci: Secure Digital Host Controller Interface driver [ 1.442993] sdhci: Copyright(c) Pierre Ossman [ 1.450802] sdhci-pltfm: SDHCI platform and OF driver helper [ 1.460363] mmc0: Invalid maximum block size, assuming 512 bytes [ 1.469905] mmc0: no vmmc regulator found [ 1.477523] Registered led device: mmc0:: [ 1.524716] mmc0: SDHCI controller on sdhci-tegra.0 [sdhci-tegra.0] using ADMA [ 1.535694] mmc1: Invalid maximum block size, assuming 512 bytes [ 1.546965] mmc1: no vmmc regulator found [ 1.557964] Registered led device: mmc1:: [ 1.603176] mmc1: SDHCI controller on sdhci-tegra.3 [sdhci-tegra.3] using ADMA [ 1.863003] mmc0: new high speed SDHC card at address aaaa [ 1.888671] mmcblk0: mmc0:aaaa SD16G 14.8 GiB [ 1.918111] mmcblk0: p1 [ 2.022258] mmc1 switching: index: 175 value: 1 set: 1 timeout: 0 [ 2.039804] mmc1 return status is: 0x00000900 [ 2.046419] mmc1 switching: index: 185 value: 1 set: 1 timeout: 0 [ 2.069361] mmc1 return status is: 0x00000900 [ 2.075991] mmc1: exec mmc_switch with val 3 and time 0 [ 2.088771] mmc1 switching: index: 187 value: 3 set: 1 timeout: 0 [ 2.097515] mmc1 return status is: 0x00000980 [ 2.104200] mmc1: power class selection for ext_csd_bus_width 2 failed [ 2.113093] mmc1: error -74 whilst initialising MMC card [ 2.275468] mmc1 switching: index: 175 value: 1 set: 1 timeout: 0 [ 2.293980] mmc1 return status is: 0x00000900 [ 2.300754] mmc1 switching: index: 185 value: 1 set: 1 timeout: 0 [ 2.310502] mmc1 return status is: 0x00000900 [ 2.317268] mmc1: exec mmc_switch with val 3 and time 0 [ 2.324874] mmc1 switching: index: 187 value: 3 set: 1 timeout: 0 [ 2.333719] mmc1 return status is: 0x00000980 [ 2.340434] mmc1: power class selection for ext_csd_bus_width 2 failed [ 2.349381] mmc1: error -74 whilst initialising MMC card [ 2.485465] mmc1 switching: index: 175 value: 1 set: 1 timeout: 0 [ 2.495166] mmc1 return status is: 0x00000900 [ 2.501866] mmc1 switching: index: 185 value: 1 set: 1 timeout: 0 [ 2.511521] mmc1 return status is: 0x00000900 [ 2.518173] mmc1: exec mmc_switch with val 3 and time 0 [ 2.525707] mmc1 switching: index: 187 value: 3 set: 1 timeout: 0 [ 2.543724] mmc1 return status is: 0x00000980 [ 2.550504] mmc1: power class selection for ext_csd_bus_width 2 failed [ 2.559483] mmc1: error -74 whilst initialising MMC card [ 2.695482] mmc1 switching: index: 175 value: 1 set: 1 timeout: 0 [ 2.705240] mmc1 return status is: 0x00000900 [ 2.711978] mmc1 switching: index: 185 value: 1 set: 1 timeout: 0 [ 2.721699] mmc1 return status is: 0x00000900 [ 2.728424] mmc1: exec mmc_switch with val 3 and time 0 [ 2.736031] mmc1 switching: index: 187 value: 3 set: 1 timeout: 0 [ 2.744870] mmc1 return status is: 0x00000980 [ 2.751604] mmc1: power class selection for ext_csd_bus_width 2 failed [ 2.760558] mmc1: error -74 whilst initialising MMC card Anything I can do to resolve this? Marc On Monday 16 April 2012 15:25:55 Shashidhar Hiremath wrote: > Hi, > is the 8bit bus width supported by the hardware ? > > On Fri, Apr 13, 2012 at 11:29 PM, Marc Dietrich <marvin24@xxxxxx> wrote: > > Hi, > > > > I'm running linux-next on a tegra-sdhci host which has a Toshiba > > THGBM2G6D2FBAI9 eMMC connected. During boot I get a "mmc1: power class > > selection to bus width 8 failed" warning. > > > > /sys/kernel/debug/mmc1# cat ios > > clock: 48000000 Hz > > actual clock: 48000000 Hz > > vdd: 20 (3.2 ~ 3.3 V) > > bus mode: 2 (push-pull) > > chip select: 0 (don't care) > > power mode: 2 (on) > > bus width: 3 (8 bits) > > timing spec: 1 (mmc high-speed) -- 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
