On 9 November 2015 at 14:30, Stephen Boyd <sboyd@xxxxxxxxxxxxxx> wrote: > All these clock controllers are little endian devices, but so far > we've been relying on the regmap mmio bus handling this for us > without explicitly stating that fact. After commit 4a98da2164cf > (regmap-mmio: Use native endianness for read/write, 2015-10-29), > the regmap mmio bus will read/write with the __raw_*() IO > accessors, instead of using the readl/writel() APIs that do > proper byte swapping for little endian devices. > > So if we're running on a big endian processor and haven't > specified the endianness explicitly in the regmap config or in > DT, we're going to switch from doing little endian byte swapping > to big endian accesses without byte swapping, leading to some > confusing results. On my apq8074 dragonboard, this causes the > device to fail to boot as we access the clock controller with > big endian IO accesses even though the device is little endian. > > Specify the endianness explicitly so that the regmap core > properly byte swaps the accesses for us. > > Reported-by: Kevin Hilman <khilman@xxxxxxxxxx> > Cc: Simon Arlott <simon@xxxxxxxxxxx> > Cc: Mark Brown <broonie@xxxxxxxxxx> > Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> Tested-by: Tyler Baker <tyler.baker@xxxxxxxxxx> The kernelci.org bot also reported boot failures[1] for the apq8016-sbc in next-20151120 with CONFIG_CPU_BIG_ENDIAN=y enabled. I've bisected the failure down to the same offending remap-mmio patch listed above. I've confirmed this patch applied on top of next-20151120 fixes the boot issue for the apq8016-sbc as well. Any updates or comments on this patch? I'd like to see this fix in linux-next, as it has been broken for over a week and could be masking new issues. Cheers, Tyler [1] http://kernelci.org/boot/all/job/next/kernel/next-20151120/ -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
