HID: wacom: Have wacom_{get,set}_report retry on -EAGAIN, not -EPIPE (aef3156d) · Commits · 戴 / test

Retrying on -EPIPE makes very little sense since this typically indicates a problem that will not just disappear on its own. For instance, the USB documentation states that it will be sent if the endpoint is stalled or the device has disconnected. Instead, we should retry if -EAGAIN is received since this indicates a temporary error condition such as a busy bus. In addition to adjusting the conditions we retry under, we also log an error on failure so that we can be aware of what's going on. Signed-off-by:

Jason Gerecke <jason.gerecke@wacom.com> Reviewed-by:

Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by:

Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_sys.c

+10 −2

Original line number	Diff line number	Diff line
		@@ -35,7 +35,11 @@ static int wacom_get_report(struct hid_device hdev, u8 type, u8 buf,
		do {
		retval = hid_hw_raw_request(hdev, buf[0], buf, size, type,
		HID_REQ_GET_REPORT);
		} while ((retval == -ETIMEDOUT \|\| retval == -EPIPE) && --retries);
		} while ((retval == -ETIMEDOUT \|\| retval == -EAGAIN) && --retries);

		if (retval < 0)
		hid_err(hdev, "wacom_get_report: ran out of retries "
		"(last error = %d)\n", retval);

		return retval;
		}
		@@ -48,7 +52,11 @@ static int wacom_set_report(struct hid_device hdev, u8 type, u8 buf,
		do {
		retval = hid_hw_raw_request(hdev, buf[0], buf, size, type,
		HID_REQ_SET_REPORT);
		} while ((retval == -ETIMEDOUT \|\| retval == -EPIPE) && --retries);
		} while ((retval == -ETIMEDOUT \|\| retval == -EAGAIN) && --retries);

		if (retval < 0)
		hid_err(hdev, "wacom_set_report: ran out of retries "
		"(last error = %d)\n", retval);

		return retval;
		}

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