Hi Marek,
On Fri, Jul 15, 2022 at 05:59:05PM +0200, Marek Vasut wrote:
> Probe the touch controller driver even if resolution information is not
> available. This can happen e.g. in case the touch controller suffered a
> failed firmware update and is stuck in bootloader mode.
>
> Signed-off-by: Marek Vasut <marex@xxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Cc: Joe Hung <joe_hung@xxxxxxxxxx>
> Cc: Luca Hsu <luca_hsu@xxxxxxxxxx>
> ---
> drivers/input/touchscreen/ili210x.c | 27 ++++++++++++++++++---------
> 1 file changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/input/touchscreen/ili210x.c b/drivers/input/touchscreen/ili210x.c
> index e9bd36adbe47d..ad25081e301c6 100644
> --- a/drivers/input/touchscreen/ili210x.c
> +++ b/drivers/input/touchscreen/ili210x.c
> @@ -370,22 +370,32 @@ static int ili251x_firmware_update_resolution(struct device *dev)
>
> /* The firmware update blob might have changed the resolution. */
> error = priv->chip->read_reg(client, REG_PANEL_INFO, &rs, sizeof(rs));
> - if (error)
> - return error;
> + if (!error) {
> + resx = le16_to_cpup((__le16 *)rs);
> + resy = le16_to_cpup((__le16 *)(rs + 2));
>
> - resx = le16_to_cpup((__le16 *)rs);
> - resy = le16_to_cpup((__le16 *)(rs + 2));
> + /* The value reported by the firmware is invalid. */
> + if (!resx || resx == 0xffff || !resy || resy == 0xffff)
> + error = -EINVAL;
> + }
>
> - /* The value reported by the firmware is invalid. */
> - if (!resx || resx == 0xffff || !resy || resy == 0xffff)
> - return -EINVAL;
> + /*
> + * In case of error, the firmware might be stuck in bootloader mode,
> + * e.g. after a failed firmware update. Set maximum resolution, but
> + * do not fail to probe, so the user can re-trigger the firmware
> + * update and recover the touch controller.
> + */
> + if (error) {
Do you want to maybe dev_warn() here to explain the weird values?
> + resx = 16384;
> + resy = 16384;
> + }
Thanks.
--
Dmitry
