On Thu, Oct 24, 2019 at 11:57:23PM +0200, Hans de Goede wrote: > The iGPU / GFX0 device's _PS0 method on the ASUS T200TA depends on the > I2C1 controller (which is connected to the embedded controller). But unlike > in the T100TA/T100CHI this dependency is not listed in the _DEP of the GFX0 > device. > > This results in the dev_WARN_ONCE(..., "Transfer while suspended\n") call > in i2c-designware-master.c triggering and the AML code not working as it > should. > > This commit fixes this by adding a dmi based quirk mechanism for devices > which miss a _DEP, and adding a quirk for the LNXVIDEO depending on the > I2C1 device on the Asus T200TA. Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> One comment below. > Cc: stable@xxxxxxxxxxxxxxx > Fixes: 2d71ee0ce72f ("ACPI / LPSS: Add a device link from the GPU to the BYT I2C5 controller") > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> > --- > Changes in v2: > -Add Fixes: tag > > Changes in v3: > -Point Fixes tag to a more apropriate commit > --- > drivers/acpi/acpi_lpss.c | 22 +++++++++++++++++++--- > 1 file changed, 19 insertions(+), 3 deletions(-) > > diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c > index cd8cf3333f04..751ed38f2a10 100644 > --- a/drivers/acpi/acpi_lpss.c > +++ b/drivers/acpi/acpi_lpss.c > @@ -10,6 +10,7 @@ > #include <linux/acpi.h> > #include <linux/clkdev.h> > #include <linux/clk-provider.h> > +#include <linux/dmi.h> > #include <linux/err.h> > #include <linux/io.h> > #include <linux/mutex.h> > @@ -463,6 +464,18 @@ struct lpss_device_links { > const char *consumer_hid; > const char *consumer_uid; > u32 flags; > + const struct dmi_system_id *dep_missing_ids; > +}; > + > +/* Please keep this list sorted alphabetically by vendor and model */ > +static const struct dmi_system_id i2c1_dep_missing_dmi_ids[] = { > + { > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."), > + DMI_MATCH(DMI_PRODUCT_NAME, "T200TA"), > + }, > + }, > + {} > }; > > /* > @@ -478,7 +491,8 @@ static const struct lpss_device_links lpss_device_links[] = { > /* CHT iGPU depends on PMIC I2C controller */ > {"808622C1", "7", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME}, > /* BYT iGPU depends on the Embedded Controller I2C controller (UID 1) */ > - {"80860F41", "1", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME}, > + {"80860F41", "1", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME, > + i2c1_dep_missing_dmi_ids}, > /* BYT CR iGPU depends on PMIC I2C controller (UID 5 on CR) */ > {"80860F41", "5", "LNXVIDEO", NULL, DL_FLAG_PM_RUNTIME}, > /* BYT iGPU depends on PMIC I2C controller (UID 7 on non CR) */ > @@ -577,7 +591,8 @@ static void acpi_lpss_link_consumer(struct device *dev1, > if (!dev2) > return; > > - if (acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1))) > + if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids)) > + || acpi_lpss_dep(ACPI_COMPANION(dev2), ACPI_HANDLE(dev1))) > device_link_add(dev2, dev1, link->flags); Perhaps a helper? > > put_device(dev2); > @@ -592,7 +607,8 @@ static void acpi_lpss_link_supplier(struct device *dev1, > if (!dev2) > return; > > - if (acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2))) > + if ((link->dep_missing_ids && dmi_check_system(link->dep_missing_ids)) > + || acpi_lpss_dep(ACPI_COMPANION(dev1), ACPI_HANDLE(dev2))) > device_link_add(dev1, dev2, link->flags); And use it here? > > put_device(dev2); > -- > 2.23.0 > -- With Best Regards, Andy Shevchenko