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alistair23-linux/drivers/platform
Hans de Goede 2373750057 platform/x86: intel-vbtn: Drop HP Stream x360 Convertible PC 11 from allow-list
[ Upstream commit 070222731b ]

THe HP Stream x360 Convertible PC 11 DSDT has the following VGBS function:

            Method (VGBS, 0, Serialized)
            {
                If ((^^PCI0.LPCB.EC0.ROLS == Zero))
                {
                    VBDS = Zero
                }
                Else
                {
                    VBDS = Zero
                }

                Return (VBDS) /* \_SB_.VGBI.VBDS */
            }

Which is obviously wrong, because it always returns 0 independent of the
2-in-1 being in laptop or tablet mode. This causes the intel-vbtn driver
to initially report SW_TABLET_MODE = 1 to userspace, which is known to
cause problems when the 2-in-1 is actually in laptop mode.

During earlier testing this turned out to not be a problem because the
2-in-1 would do a Notify(..., 0xCC) or Notify(..., 0xCD) soon after
the intel-vbtn driver loaded, correcting the SW_TABLET_MODE state.

Further testing however has shown that this Notify() soon after the
intel-vbtn driver loads, does not always happen. When the Notify
does not happen, then intel-vbtn reports SW_TABLET_MODE = 1 resulting in
a non-working touchpad.

IOW the tablet-mode reporting is not reliable on this device, so it
should be dropped from the allow-list, fixing the touchpad sometimes
not working.

Fixes: 8169bd3e6e ("platform/x86: intel-vbtn: Switch to an allow-list for SW_TABLET_MODE reporting")
Link: https://lore.kernel.org/r/20210114143432.31750-1-hdegoede@redhat.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-27 11:47:47 +01:00
..
chrome platform/chrome: cros_ec_spi: Don't overwrite spi::mode 2020-12-30 11:51:23 +01:00
goldfish treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mellanox platform/mellanox: fix potential deadlock in the tmfifo driver 2020-01-17 19:48:42 +01:00
mips MIPS: Loongson: Fix return value of loongson_hwmon_init 2020-01-17 19:48:55 +01:00
olpc Platform: OLPC: Fix memleak in olpc_ec_probe 2020-10-14 10:32:58 +02:00
x86 platform/x86: intel-vbtn: Drop HP Stream x360 Convertible PC 11 from allow-list 2021-01-27 11:47:47 +01:00
Kconfig platform-drivers-x86 for v5.3-1 2019-07-14 16:51:47 -07:00
Makefile Platform: OLPC: Add XO-1.75 EC driver 2019-05-20 17:27:08 +03:00