Hi Ilpo,
thank you for your comments.
I added some defines for the values of the module param and re-ordered the
logic a bit. I think it is easier to follow now.
I now also use another return variable "ret2" for the result of
hp_wmi_read_int() to not overwrite the result of original
hp_wmi_perform_query() when hp_wmi_read_int() fails. This was actually a
bug in my first implementation.
I still think that re-using the enable_tablet_mode_sw param for that is
a reasonable compromise, because the comment of original
commit 520ee4ea1cc60251a6e3c911cf0336278aa52634 suggests that there was
some problem with hp_wmi_read_int(HPWMI_HARDWARE_QUERY) on newer Tablets.
So, because I cannot test this, I'd prefer to not change current behavior
when the enable_tablet_mode_sw parameter is not set.
Best Regards
Stefan
Actual patch starts here:
From: Stefan Sichler <stsichler@xxxxxx>
Date: Mon, 19 Aug 2024 14:45:57 +0200
Subject: [PATCH] platform/x86: hp-wmi: repair Tablet Mode detection on old
Convertibles
This fixes a regression introduced by commit
520ee4ea1cc60251a6e3c911cf0336278aa52634
("Fix SW_TABLET_MODE detection method").
Investigation showed that some older Convertibles like HP EliteBook 2760p
do neither report Chassis Type correctly nor report tablet state by
HPWMI_SYSTEM_DEVICE_MODE, so for those, it is still required to fallback
to previous HPWMI_HARDWARE_QUERY method.
Since on pre-5.18 kernels, it was required to set enable_tablet_mode_sw
module param to enable this anyway, we re-add this removed parameter here
and re-use it in the following way:
- when left at default -1 (auto): no change to current implementation
- when set to 0 (off): unconditionally disable tablet mode reporting
- when set to 1 (force on): ignore Chassis type and use old
hp_wmi_hw_state(HPWMI_TABLET_MASK) query method in addition to new
hp_wmi_perform_query(HPWMI_SYSTEM_DEVICE_MODE...) method
Signed-off-by: Stefan Sichler <stsichler@xxxxxx>
---
drivers/platform/x86/hp/hp-wmi.c | 32 ++++++++++++++++++++++++++++----
1 file changed, 28 insertions(+), 4 deletions(-)
diff --git a/drivers/platform/x86/hp/hp-wmi.c b/drivers/platform/x86/hp/hp-wmi.c
index 876e0a97c..cab01308d 100644
--- a/drivers/platform/x86/hp/hp-wmi.c
+++ b/drivers/platform/x86/hp/hp-wmi.c
@@ -38,6 +38,13 @@ MODULE_LICENSE("GPL");
MODULE_ALIAS("wmi:95F24279-4D7B-4334-9387-ACCDC67EF61C");
MODULE_ALIAS("wmi:5FB7F034-2C63-45E9-BE91-3D44E2C707E4");
+static int enable_tablet_mode_sw = -1;
+module_param(enable_tablet_mode_sw, int, 0444);
+MODULE_PARM_DESC(enable_tablet_mode_sw, "Enable SW_TABLET_MODE reporting (-1=auto, 0=no, 1=yes)");
+#define HPWMI_TABLET_MODE_SW_AUTO -1
+#define HPWMI_TABLET_MODE_SW_OFF 0
+#define HPWMI_TABLET_MODE_SW_FORCE_ON 1
+
#define HPWMI_EVENT_GUID "95F24279-4D7B-4334-9387-ACCDC67EF61C"
#define HPWMI_BIOS_GUID "5FB7F034-2C63-45E9-BE91-3D44E2C707E4"
@@ -459,23 +466,40 @@ static int hp_wmi_get_tablet_mode(void)
bool tablet_found;
int ret;
+ if (enable_tablet_mode_sw == HPWMI_TABLET_MODE_SW_OFF)
+ return -ENODEV;
+
chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
if (!chassis_type)
return -ENODEV;
- tablet_found = match_string(tablet_chassis_types,
+ tablet_found =
+ (enable_tablet_mode_sw == HPWMI_TABLET_MODE_SW_FORCE_ON)
+ || (match_string(tablet_chassis_types,
ARRAY_SIZE(tablet_chassis_types),
- chassis_type) >= 0;
+ chassis_type) >= 0);
if (!tablet_found)
return -ENODEV;
ret = hp_wmi_perform_query(HPWMI_SYSTEM_DEVICE_MODE, HPWMI_READ,
system_device_mode, zero_if_sup(system_device_mode),
sizeof(system_device_mode));
- if (ret < 0)
+ if (ret < 0 && enable_tablet_mode_sw != HPWMI_TABLET_MODE_SW_FORCE_ON)
return ret;
- return system_device_mode[0] == DEVICE_MODE_TABLET;
+ if (ret >= 0)
+ ret = (system_device_mode[0] == DEVICE_MODE_TABLET);
+
+ /* workaround for older convertibles. needs to be actively switched on
+ * and is only executed when HPWMI_SYSTEM_DEVICE_MODE query failed or
+ * did not report tablet state, i.e. (ret < 0) or (ret == 0) */
+ if (ret <= 0 && enable_tablet_mode_sw == HPWMI_TABLET_MODE_SW_FORCE_ON) {
+ int ret2 = hp_wmi_read_int(HPWMI_HARDWARE_QUERY);
+ if (ret2 >= 0)
+ ret = !!(ret2 & HPWMI_TABLET_MASK);
+ }
+
+ return ret;
}
static int omen_thermal_profile_set(int mode)
--
2.43.0
