On 11/20, Tyler Baker wrote: > 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. Yeah I've been lagging on applying patches. I need to send more patches for other regmap-mmio users too. I'll cook those up right now and send them off. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- 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
