]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
mfd: intel-lpss: Use devm_ioremap_uc for MMIO
authorTuowen Zhao <ztuowen@gmail.com>
Tue, 26 Nov 2019 05:03:08 +0000 (13:03 +0800)
committerStefan Bader <stefan.bader@canonical.com>
Wed, 4 Dec 2019 09:29:26 +0000 (10:29 +0100)
commitfd8df413dae94654956e6f8eff83c7dde66409ba
tree9355f531d50a52b9e58cb3addba68eee4537d48d
parente8fc2dd6c97d79a64a530772e5db0545c0aa68b8
mfd: intel-lpss: Use devm_ioremap_uc for MMIO

BugLink: https://bugs.launchpad.net/bugs/1851901
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>
(cherry picked from commit a8ff78f7f773142eb8a8befe5a95dd6858ebd635 linux-next)
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Anthony Wong <anthony.wong@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
drivers/mfd/intel-lpss.c