linux-kernel - [PATCH 4.19 26/58] platform/x86: intel-vbtn: Drop HP Stream x360 Convertible PC 11 from allow-list

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Date:   Mon, 25 Jan 2021 19:39:27 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Hans de Goede <hdegoede@...hat.com>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 26/58] platform/x86: intel-vbtn: Drop HP Stream x360 Convertible PC 11 from allow-list

From: Hans de Goede <hdegoede@...hat.com>

[ Upstream commit 070222731be52d741e55d8967b1764482b81e54c ]

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: 8169bd3e6e19 ("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@...hat.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/platform/x86/intel-vbtn.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/platform/x86/intel-vbtn.c b/drivers/platform/x86/intel-vbtn.c
index 36d6e72f50735..f5774372c3871 100644
--- a/drivers/platform/x86/intel-vbtn.c
+++ b/drivers/platform/x86/intel-vbtn.c
@@ -191,12 +191,6 @@ static const struct dmi_system_id dmi_switches_allow_list[] = {
 			DMI_MATCH(DMI_PRODUCT_NAME, "Venue 11 Pro 7130"),
 		},
 	},
-	{
-		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
-			DMI_MATCH(DMI_PRODUCT_NAME, "HP Stream x360 Convertible PC 11"),
-		},
-	},
 	{
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
-- 
2.27.0