Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Tue, 10 Dec 2019 09:11:43 +0100 | Subject | Re: [PATCH v5 3/4] mfd: intel-lpss: use devm_ioremap_uc for MMIO |
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CC Christoph (ioremap() API cleanup)
On Thu, Oct 17, 2019 at 10:44 PM Tuowen Zhao <ztuowen@gmail.com> 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@vger.kernel.org> > Tested-by: AceLan Kao <acelan.kao@canonical.com> > Signed-off-by: Tuowen Zhao <ztuowen@gmail.com> > Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> > Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Acked-for-MFD-by: Lee Jones <lee.jones@linaro.org> > --- > drivers/mfd/intel-lpss.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c > index bfe4ff337581..b0f0781a6b9c 100644 > --- a/drivers/mfd/intel-lpss.c > +++ b/drivers/mfd/intel-lpss.c > @@ -384,7 +384,7 @@ int intel_lpss_probe(struct device *dev, > if (!lpss) > return -ENOMEM; > > - lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET, > + lpss->priv = devm_ioremap_uc(dev, info->mem->start + LPSS_PRIV_OFFSET, > LPSS_PRIV_SIZE); > if (!lpss->priv) > return -ENOMEM;
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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