This is a note to let you know that I've just added the patch titled
media: atomisp_gmin_platform: Add DMI quirk to not turn AXP ELDO2 regulator off on some boards
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-atomisp_gmin_platform-add-dmi-quirk-to-not-tur.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 9fcb4d855136baaced8d804fa0616d90216f5368
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Sun Jan 16 22:52:04 2022 +0100
media: atomisp_gmin_platform: Add DMI quirk to not turn AXP ELDO2 regulator off on some boards
[ Upstream commit 2c39a01154ea57d596470afa1d278e3be3b37f6a ]
The TrekStor SurfTab duo W1 10.1 has a hw bug where turning eldo2 back on
after having turned it off causes the CPLM3218 ambient-light-sensor on
the front camera sensor's I2C bus to crash, hanging the bus.
Add a DMI quirk table for systems on which to leave eldo2 on.
Note an alternative fix is to turn off the CPLM3218 ambient-light-sensor
as long as the camera sensor is being used, this is what Windows seems
to do as a workaround (based on analyzing the DSDT). But that is not
easy to do cleanly under Linux.
Link: https://lore.kernel.org/linux-media/20220116215204.307649-10-hdegoede@xxxxxxxxxx
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
index 62dc06e22476..cd0a771454da 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c
@@ -729,6 +729,21 @@ static int axp_regulator_set(struct device *dev, struct gmin_subdev *gs,
return 0;
}
+/*
+ * Some boards contain a hw-bug where turning eldo2 back on after having turned
+ * it off causes the CPLM3218 ambient-light-sensor on the image-sensor's I2C bus
+ * to crash, hanging the bus. Do not turn eldo2 off on these systems.
+ */
+static const struct dmi_system_id axp_leave_eldo2_on_ids[] = {
+ {
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "TrekStor"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "SurfTab duo W1 10.1 (VT4)"),
+ },
+ },
+ { }
+};
+
static int axp_v1p8_on(struct device *dev, struct gmin_subdev *gs)
{
int ret;
@@ -763,6 +778,9 @@ static int axp_v1p8_off(struct device *dev, struct gmin_subdev *gs)
if (ret)
return ret;
+ if (dmi_check_system(axp_leave_eldo2_on_ids))
+ return 0;
+
ret = axp_regulator_set(dev, gs, gs->eldo2_sel_reg, gs->eldo2_1p8v,
ELDO_CTRL_REG, gs->eldo2_ctrl_shift, false);
return ret;
