Patch "platform/x86: touchscreen_dmi: Allow partial (prefix) matches for ACPI names" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    platform/x86: touchscreen_dmi: Allow partial (prefix) matches for ACPI names

to the 5.10-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:
     platform-x86-touchscreen_dmi-allow-partial-prefix-ma.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 6652e92a0f68735e1adc2d4acb3de57241ae0d74
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date:   Mon Feb 12 13:06:07 2024 +0100

    platform/x86: touchscreen_dmi: Allow partial (prefix) matches for ACPI names
    
    [ Upstream commit dbcbfd662a725641d118fb3ae5ffb7be4e3d0fb0 ]
    
    On some devices the ACPI name of the touchscreen is e.g. either
    MSSL1680:00 or MSSL1680:01 depending on the BIOS version.
    
    This happens for example on the "Chuwi Hi8 Air" tablet where the initial
    commit's ts_data uses "MSSL1680:00" but the tablets from the github issue
    and linux-hardware.org probe linked below both use "MSSL1680:01".
    
    Replace the strcmp() match on ts_data->acpi_name with a strstarts()
    check to allow using a partial match on just the ACPI HID of "MSSL1680"
    and change the ts_data->acpi_name for the "Chuwi Hi8 Air" accordingly
    to fix the touchscreen not working on models where it is "MSSL1680:01".
    
    Note this drops the length check for I2C_NAME_SIZE. This never was
    necessary since the ACPI names used are never more then 11 chars and
    I2C_NAME_SIZE is 20 so the replaced strncmp() would always stop long
    before reaching I2C_NAME_SIZE.
    
    Link: https://linux-hardware.org/?computer=AC4301C0542A
    Fixes: bbb97d728f77 ("platform/x86: touchscreen_dmi: Add info for the Chuwi Hi8 Air tablet")
    Closes: https://github.com/onitake/gsl-firmware/issues/91
    Cc: stable@xxxxxxxxxxxxxxx
    Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
    Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240212120608.30469-1-hdegoede@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/platform/x86/touchscreen_dmi.c b/drivers/platform/x86/touchscreen_dmi.c
index fd22f6778664b..fb5c84872d322 100644
--- a/drivers/platform/x86/touchscreen_dmi.c
+++ b/drivers/platform/x86/touchscreen_dmi.c
@@ -50,7 +50,7 @@ static const struct property_entry chuwi_hi8_air_props[] = {
 };
 
 static const struct ts_dmi_data chuwi_hi8_air_data = {
-	.acpi_name	= "MSSL1680:00",
+	.acpi_name	= "MSSL1680",
 	.properties	= chuwi_hi8_air_props,
 };
 
@@ -1648,7 +1648,7 @@ static void ts_dmi_add_props(struct i2c_client *client)
 	int error;
 
 	if (has_acpi_companion(dev) &&
-	    !strncmp(ts_data->acpi_name, client->name, I2C_NAME_SIZE)) {
+	    strstarts(client->name, ts_data->acpi_name)) {
 		error = device_create_managed_software_node(dev, ts_data->properties, NULL);
 		if (error)
 			dev_err(dev, "failed to add properties: %d\n", error);