[PATCH 6.6 34/86] HID: intel-ish-hid: Reset enum_devices_done before enumeration

Greg Kroah-Hartman
2026-02-09T14:47:04Z

From: Zhang Lixu <lixu.zhang@intel.com>

[ Upstream commit 56e230723e3a818373bd62331bccb1c6d2b3881b ]

Some systems have enabled ISH without any sensors. In this case sending
HOSTIF_DM_ENUM_DEVICES results in 0 sensors. This triggers ISH hardware
reset on subsequent enumeration after S3/S4 resume.

The enum_devices_done flag was not reset before sending the
HOSTIF_DM_ENUM_DEVICES command. On subsequent enumeration calls (such as
after S3/S4 resume), this flag retains its previous true value, causing the
wait loop to be skipped and returning prematurely to hid_ishtp_cl_init().
If 0 HID devices are found, hid_ishtp_cl_init() skips getting HID device
descriptors and sets init_done to true. When the delayed enumeration
response arrives with init_done already true, the driver treats it as a bad
packet and triggers an ISH hardware reset.

Set enum_devices_done to false before sending the enumeration command,
consistent with similar functions like ishtp_get_hid_descriptor() and
ishtp_get_report_descriptor() which reset their respective flags.

Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hid/intel-ish-hid/ishtp-hid-client.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/hid/intel-ish-hid/ishtp-hid-client.c b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
index e3d70c5460e96..a0c1dc0941497 100644
--- a/drivers/hid/intel-ish-hid/ishtp-hid-client.c
+++ b/drivers/hid/intel-ish-hid/ishtp-hid-client.c
@@ -496,6 +496,7 @@ static int ishtp_enum_enum_devices(struct ishtp_cl *hid_ishtp_cl)
int rv;

/* Send HOSTIF_DM_ENUM_DEVICES */
+ client_data->enum_devices_done = false;
memset(&msg, 0, sizeof(struct hostif_msg));
msg.hdr.command = HOSTIF_DM_ENUM_DEVICES;
rv = ishtp_cl_send(hid_ishtp_cl, (unsigned char *)&msg,
--
2.51.0