Re: [PATCH v5 3/4] mfd: intel-lpss: use devm_ioremap_uc for MMIO

[Lee Jones]

On Wed, 16 Oct 2019, Tuowen Zhao wrote:

> Some BIOS erroneously specifies write-combining BAR for intel-lpss-pci
> in MTRR. This will cause the system to hang during boot. If possible,
> this bug could be corrected with a firmware update.
> 
> This patch use devm_ioremap_uc to overwrite/ignore the MTRR settings
> by forcing the use of strongly uncachable pages for intel-lpss.
> 
> The BIOS bug is present on Dell XPS 13 7390 2-in-1:
> 
> [    0.001734]   5 base 4000000000 mask 6000000000 write-combining
> 
> 4000000000-7fffffffff : PCI Bus 0000:00
>   4000000000-400fffffff : 0000:00:02.0 (i915)
>   4010000000-4010000fff : 0000:00:15.0 (intel-lpss-pci)
> 
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203485
> Cc: <stable@xxxxxxxxxxxxxxx>
> Tested-by: AceLan Kao <acelan.kao@xxxxxxxxxxxxx>
> Signed-off-by: Tuowen Zhao <ztuowen@xxxxxxxxx>
> Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> Acked-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Acked-for-MFD-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
>  drivers/mfd/intel-lpss.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Applied, thanks.

-- 
Lee Jones [æçæ]
Linaro Services Technical Lead
Linaro.org â Open source software for ARM SoCs
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