mfd: cros_ec: Read EC features during probe to catch transfer error

cros_ec_check_features() does not return an error if the underlying
EC_CMD_GET_FEATURES command fails. Consequently, when the Fingerprint
device fails to respond, the probe function ignores the failure and falls
back to installing it as 'cros_ec' device instead of 'cros_fp'.
This leads to a sysfs duplicate filename collision later when the real
'cros_ec' device attempts to register:

  cros-ec-spi spi5.0: EC failed to respond in time
  cros-ec-dev.19.auto: cannot get EC features: -110
  sysfs : cannot create duplicate filename '/class/chromeos/cros_ec'
        : sysfs_do_create_link_sd+0x94/0xdc
        : ec_device_probe+0x150/0x4f0

Fix this by explicitly calling the newly introduced cros_ec_read_features()
function. If the transfer fails, abort the broken device initialization.
Move the initialization of class_dev before this call to prevent a missing
release() callback warning on the error path.

Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
Link: https://patch.msgid.link/20260608211518.2214740-3-akuchynski@chromium.org
Signed-off-by: Lee Jones <lee@kernel.org>
This commit is contained in:
Andrei Kuchynski 2026-06-08 21:15:18 +00:00 • committed by Lee Jones
commit 5855464dff