Commit aba79635 authored by Mavroudis Chatzilazaridis's avatar Mavroudis Chatzilazaridis Committed by Jiri Kosina
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HID: logitech-hidpp: Do not assume FAP in hidpp_send_message_sync() 



Currently, hidpp_send_message_sync() retries sending the message when the
device returns a busy error code, specifically HIDPP20_ERROR_BUSY, which
has a different meaning under RAP. This ends up being a problem because
this function is used for both FAP and RAP messages.

This issue is not noticeable on older receivers with unreachable devices
since they return HIDPP_ERROR_RESOURCE_ERROR (0x09), which is not equal to
HIDPP20_ERROR_BUSY (0x08).

However, newer receivers return HIDPP_ERROR_UNKNOWN_DEVICE (0x08) which
happens to equal to HIDPP20_ERROR_BUSY, causing unnecessary retries when
the device is not actually busy.

This is resolved by checking if the error response is FAP or RAP and
picking the respective ERROR_BUSY code.

Fixes: 60165ab7 ("HID: logitech-hidpp: rework one more time the retries attempts")
Signed-off-by: default avatarMavroudis Chatzilazaridis <mavchatz@protonmail.com>
Tested-by: default avatarStuart Hayhurst <stuart.a.hayhurst@gmail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.com>
parent 55cafcac

drivers/hid/hid-logitech-hidpp.c

+7 −2
Original line number Diff line number Diff line
@@ -350,10 +350,15 @@ static int hidpp_send_message_sync(struct hidpp_device *hidpp, 


	do {

		ret = __do_hidpp_send_message_sync(hidpp, message, response);

		if (ret != HIDPP20_ERROR_BUSY)

		if (response->report_id == REPORT_ID_HIDPP_SHORT &&

		    ret != HIDPP_ERROR_BUSY)

			break;

		if ((response->report_id == REPORT_ID_HIDPP_LONG ||

		     response->report_id == REPORT_ID_HIDPP_VERY_LONG) &&

		    ret != HIDPP20_ERROR_BUSY)

			break;



		dbg_hid("%s:got busy hidpp 2.0 error %02X, retrying\n", __func__, ret);

		dbg_hid("%s:got busy hidpp error %02X, retrying\n", __func__, ret);

	} while (--max_retries);



	mutex_unlock(&hidpp->send_mutex);