linux-kernel - [PATCH 5.14 123/849] HID: surface-hid: Use correct event registry for managing HID events

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Date:   Mon, 15 Nov 2021 17:53:26 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Maximilian Luz <luzmaximilian@...il.com>,
        Benjamin Tissoires <benjamin.tissoires@...hat.com>,
        Hans de Goede <hdegoede@...hat.com>
Subject: [PATCH 5.14 123/849] HID: surface-hid: Use correct event registry for managing HID events

From: Maximilian Luz <luzmaximilian@...il.com>

commit dc0fd0acb6e0e8025a0a43ada54513b216254fac upstream.

Until now, we have only ever seen the REG-category registry being used
on devices addressed with target ID 2. In fact, we have only ever seen
Surface Aggregator Module (SAM) HID devices with target ID 2. For those
devices, the registry also has to be addressed with target ID 2.

Some devices, like the new Surface Laptop Studio, however, address their
HID devices on target ID 1. As a result of this, any target ID 2
commands time out. This includes event management commands addressed to
the target ID 2 REG-category registry. For these devices, the registry
has to be addressed via target ID 1 instead.

We therefore assume that the target ID of the registry to be used
depends on the target ID of the respective device. Implement this
accordingly.

Note that we currently allow the surface HID driver to only load against
devices with target ID 2, so these timeouts are not happening (yet).
This is just a preparation step before we allow the driver to load
against all target IDs.

Cc: stable@...r.kernel.org # 5.14+
Signed-off-by: Maximilian Luz <luzmaximilian@...il.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@...hat.com>
Link: https://lore.kernel.org/r/20211021130904.862610-3-luzmaximilian@gmail.com
Reviewed-by: Hans de Goede <hdegoede@...hat.com>
Signed-off-by: Hans de Goede <hdegoede@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/hid/surface-hid/surface_hid.c         |    2 +-
 include/linux/surface_aggregator/controller.h |    4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/hid/surface-hid/surface_hid.c
+++ b/drivers/hid/surface-hid/surface_hid.c
@@ -209,7 +209,7 @@ static int surface_hid_probe(struct ssam

 	shid->notif.base.priority = 1;
 	shid->notif.base.fn = ssam_hid_event_fn;
-	shid->notif.event.reg = SSAM_EVENT_REGISTRY_REG;
+	shid->notif.event.reg = SSAM_EVENT_REGISTRY_REG(sdev->uid.target);
 	shid->notif.event.id.target_category = sdev->uid.category;
 	shid->notif.event.id.instance = sdev->uid.instance;
 	shid->notif.event.mask = SSAM_EVENT_MASK_STRICT;
--- a/include/linux/surface_aggregator/controller.h
+++ b/include/linux/surface_aggregator/controller.h
@@ -792,8 +792,8 @@ enum ssam_event_mask {
 #define SSAM_EVENT_REGISTRY_KIP	\
 	SSAM_EVENT_REGISTRY(SSAM_SSH_TC_KIP, 0x02, 0x27, 0x28)

-#define SSAM_EVENT_REGISTRY_REG \
-	SSAM_EVENT_REGISTRY(SSAM_SSH_TC_REG, 0x02, 0x01, 0x02)
+#define SSAM_EVENT_REGISTRY_REG(tid)\
+	SSAM_EVENT_REGISTRY(SSAM_SSH_TC_REG, tid, 0x01, 0x02)

 /**
  * enum ssam_event_notifier_flags - Flags for event notifiers.