Commit 372ee6a3 authored by Hans de Goede's avatar Hans de Goede Committed by Greg Kroah-Hartman
Browse files

usb: misc: ljca: Fix enumeration error on Dell Latitude 9420 



Not all LJCA chips implement SPI and on chips without SPI reading
the SPI descriptors will timeout.

On laptop models like the Dell Latitude 9420, this is expected behavior
and not an error.

Modify the driver to continue without instantiating a SPI auxbus child,
instead of failing to probe() the whole LJCA chip.

Fixes: acd6199f ("usb: Add support for Intel LJCA device")
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Reviewed-by: default avatarWentong Wu <wentong.wu@intel.com>
Link: https://lore.kernel.org/r/20231104175104.38786-1-hdegoede@redhat.com
Link: https://lore.kernel.org/r/20231121203205.223047-1-hdegoede@redhat.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 16b7e0cc

drivers/usb/misc/usb-ljca.c

+2 −1
Original line number Diff line number Diff line
@@ -646,10 +646,11 @@ static int ljca_enumerate_spi(struct ljca_adapter *adap) 
	unsigned int i;

	int ret;



	/* Not all LJCA chips implement SPI, a timeout reading the descriptors is normal */

	ret = ljca_send(adap, LJCA_CLIENT_MNG, LJCA_MNG_ENUM_SPI, NULL, 0, buf,

			sizeof(buf), true, LJCA_ENUM_CLIENT_TIMEOUT_MS);

	if (ret < 0)

		return ret;

		return (ret == -ETIMEDOUT) ? 0 : ret;



	/* check firmware response */

	desc = (struct ljca_spi_descriptor *)buf;