From aba7963544d47d82cdf36602a6678a093af0299d Mon Sep 17 00:00:00 2001 From: Mavroudis Chatzilazaridis Date: Thu, 2 Oct 2025 19:30:58 +0000 Subject: [PATCH] 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: 60165ab774cb ("HID: logitech-hidpp: rework one more time the retries attempts") Signed-off-by: Mavroudis Chatzilazaridis Tested-by: Stuart Hayhurst Signed-off-by: Jiri Kosina --- drivers/hid/hid-logitech-hidpp.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c index 1d46783384ede..690fecd5b9e0e 100644 --- a/drivers/hid/hid-logitech-hidpp.c +++ b/drivers/hid/hid-logitech-hidpp.c @@ -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); -- 2.47.3