diff options
| author |   Tuowen Zhao <ztuowen@gmail.com> | 2019-10-16 15:06:29 -0600 |
|---|---|---|
| committer |   Lee Jones <lee.jones@linaro.org> | 2019-11-11 08:40:21 +0000 |
| commit | a8ff78f7f773142eb8a8befe5a95dd6858ebd635 (patch) | |
| tree | 4074c52baf7fd1253450eafe4ea57d534e761b90 /drivers/mfd | |
| parent | lib: devres: add a helper function for ioremap_uc (diff) | |
| download | linux-dev-a8ff78f7f773142eb8a8befe5a95dd6858ebd635.tar.xz linux-dev-a8ff78f7f773142eb8a8befe5a95dd6858ebd635.zip | |
mfd: intel-lpss: Use devm_ioremap_uc for MMIO
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>
Diffstat (limited to 'drivers/mfd')
| -rw-r--r-- | drivers/mfd/intel-lpss.c | 2 |
1 files changed, 1 insertions, 1 deletions
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; |