| Message ID | 20201211021814.36193-1-hui.wang@canonical.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | [v4] ACPI / PNP: compare the string length in the matching_id | expand |
On Fri, Dec 11, 2020 at 3:19 AM Hui Wang <hui.wang@canonical.com> wrote: > > Recently we met a touchscreen problem on some Thinkpad machines, the > touchscreen driver (i2c-hid) is not loaded and the touchscreen can't > work. > > An i2c ACPI device with the name WACF2200 is defined in the BIOS, with > the current rule in matching_id(), this device will be regarded as > a PNP device since there is WACFXXX in the acpi_pnp_device_ids[] and > this PNP device is attached to the acpi device as the 1st > physical_node, this will make the i2c bus match fail when i2c bus > calls acpi_companion_match() to match the acpi_id_table in the i2c-hid > driver. > > WACF2200 is an i2c device instead of a PNP device, after adding the > string length comparing, the matching_id() will return false when > matching WACF2200 and WACFXXX, and it is reasonable to compare the > string length when matching two ids. > > Cc: stable@vger.kernel.org > Signed-off-by: Hui Wang <hui.wang@canonical.com> > --- > Sorry, the v3 patch has mis-spelling word in the commit header, so fix > it and send the v4 patch. > > drivers/acpi/acpi_pnp.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/acpi/acpi_pnp.c b/drivers/acpi/acpi_pnp.c > index 4ed755a963aa..8f2dc176bb41 100644 > --- a/drivers/acpi/acpi_pnp.c > +++ b/drivers/acpi/acpi_pnp.c > @@ -319,6 +319,9 @@ static bool matching_id(const char *idstr, const char *list_id) > { > int i; > > + if (strlen(idstr) != strlen(list_id)) > + return false; > + > if (memcmp(idstr, list_id, 3)) > return false; > > -- Applied as 5.11-rc material, thanks!
diff --git a/drivers/acpi/acpi_pnp.c b/drivers/acpi/acpi_pnp.c index 4ed755a963aa..8f2dc176bb41 100644 --- a/drivers/acpi/acpi_pnp.c +++ b/drivers/acpi/acpi_pnp.c @@ -319,6 +319,9 @@ static bool matching_id(const char *idstr, const char *list_id) { int i; + if (strlen(idstr) != strlen(list_id)) + return false; + if (memcmp(idstr, list_id, 3)) return false;
Recently we met a touchscreen problem on some Thinkpad machines, the touchscreen driver (i2c-hid) is not loaded and the touchscreen can't work. An i2c ACPI device with the name WACF2200 is defined in the BIOS, with the current rule in matching_id(), this device will be regarded as a PNP device since there is WACFXXX in the acpi_pnp_device_ids[] and this PNP device is attached to the acpi device as the 1st physical_node, this will make the i2c bus match fail when i2c bus calls acpi_companion_match() to match the acpi_id_table in the i2c-hid driver. WACF2200 is an i2c device instead of a PNP device, after adding the string length comparing, the matching_id() will return false when matching WACF2200 and WACFXXX, and it is reasonable to compare the string length when matching two ids. Cc: stable@vger.kernel.org Signed-off-by: Hui Wang <hui.wang@canonical.com> --- Sorry, the v3 patch has mis-spelling word in the commit header, so fix it and send the v4 patch. drivers/acpi/acpi_pnp.c | 3 +++ 1 file changed, 3 insertions(+)