[PATCH] HID: intel-ish-hid: ignore post-init ENUM_DEVICES from firmware

[Wahid7852 <wahidzk0091@gmail.com>]

Some ISH firmware versions (observed on Tiger Lake LP, 8086:a0fc,
GUID {33AECD58-B679-4E54-9BD9-A04D34F0C226}) periodically re-send an
unsolicited HOSTIF_DM_ENUM_DEVICES response roughly every 79 seconds.

The current guard collapses two distinct cases into one condition:

  if (!(response_flag) || init_done)  ->  bad packet + ish_hw_reset

This incorrectly treats a valid post-init firmware announcement as a
corrupted packet, triggering an ISH soft-reset and a full ISHTP
re-initialisation cycle on each occurrence (~1100 times per day on
affected hardware).

Split the check: reject messages with no response flag as before, but
simply discard valid ENUM_DEVICES messages that arrive after init is
complete.

Signed-off-by: Wahid <wahidzk0091@gmail.com>
---
 drivers/hid/intel-ish-hid/ishtp-hid-client.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/intel-ish-hid/ishtp-hid-client.c b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
index 6d64008f2..ec5e8afe7 100644
--- a/drivers/hid/intel-ish-hid/ishtp-hid-client.c
+++ b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
@@ -113,8 +113,7 @@ static void process_recv(struct ishtp_cl *hid_ishtp_cl, void *recv_buf,
 
 		switch (recv_msg->hdr.command & CMD_MASK) {
 		case HOSTIF_DM_ENUM_DEVICES:
-			if ((!(recv_msg->hdr.command & ~CMD_MASK) ||
-					client_data->init_done)) {
+			if (!(recv_msg->hdr.command & ~CMD_MASK)) {
 				++client_data->bad_recv_cnt;
 				report_bad_packet(hid_ishtp_cl, recv_msg,
 						  cur_pos,
@@ -122,6 +121,8 @@ static void process_recv(struct ishtp_cl *hid_ishtp_cl, void *recv_buf,
 				ish_hw_reset(ishtp_get_ishtp_device(hid_ishtp_cl));
 				break;
 			}
+			if (client_data->init_done)
+				break;
 			client_data->hid_dev_count = (unsigned int)*payload;
 			if (!client_data->hid_devices)
 				client_data->hid_devices = devm_kcalloc(
-- 
2.54.0