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authorTuowen Zhao <ztuowen@gmail.com>2019-10-17 00:06:29 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-05-10 11:30:11 +0300
commite06a89985c585fb5f5e0448bf4a166de416777f8 (patch)
tree79987121faea669d48f1207e73ac3d65f38a4a6b /drivers/mfd
parentccc4433062ce800ec03f573c156b893148fcf2c6 (diff)
downloadlinux-e06a89985c585fb5f5e0448bf4a166de416777f8.tar.xz
mfd: intel-lpss: Use devm_ioremap_uc for MMIO
commit a8ff78f7f773142eb8a8befe5a95dd6858ebd635 upstream. 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> # v4.19+ 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> Tested-by: Roman Gilg <subdiff@gmail.com> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/mfd')
-rw-r--r--drivers/mfd/intel-lpss.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
index 95e217e6b6d7..7577afd42842 100644
--- a/drivers/mfd/intel-lpss.c
+++ b/drivers/mfd/intel-lpss.c
@@ -397,7 +397,7 @@ 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;