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Date:   Tue,  3 Oct 2023 19:57:24 -0500
Mime-Version: 1.0
Message-ID: <20231004005729.3943515-1-jefferymiller@google.com>
Subject: [PATCH] Input: elantech - fix fast_reconnect callback in ps2 mode
From:   Jeffery Miller <jefferymiller@google.com>
To:     Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc:     regressions@lists.linux.dev, benjamin.tissoires@redhat.com,
        linux@leemhuis.info, Andrew Duggan <aduggan@synaptics.com>,
        Andrew Duggan <andrew@duggan.us>, loic.poulain@linaro.org,
        Jeffery Miller <jefferymiller@google.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Make `elantech_setup_ps2` set a compatible fast_reconnect pointer
when its ps2 mode is used.

When an SMBus connection is attempted and fails `psmouse_smbus_init`
sets fast_reconnect to `psmouse_smbus_reconnect`.
`psmouse_smbus_reconnect` expects `psmouse->private` to be
`struct psmouse_smbus_dev` but `elantech_setup_ps2` replaces
it with its private data. This was causing an issue on resume
since psmouse_smbus_reconnect was being called while in ps2, not SMBus
mode.

This was uncovered by commit 92e24e0e57f7 ("Input: psmouse - add delay when
deactivating for SMBus mode")

Closes:
Link:https://lore.kernel.org/all/ca0109fa-c64b-43c1-a651-75b294d750a1@leemhuis.info/
Reported-by: Thorsten Leemhuis <linux@leemhuis.info>

Signed-off-by: Jeffery Miller <jefferymiller@google.com>
---

The other callbacks set in psmouse_smbus_init are already replaced.
Should fast_reconnect be set to `elantech_reconnect` instead?


 drivers/input/mouse/elantech.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index 2118b2075f43..4e38229404b4 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -2114,6 +2114,7 @@ static int elantech_setup_ps2(struct psmouse *psmouse,
 	psmouse->protocol_handler = elantech_process_byte;
 	psmouse->disconnect = elantech_disconnect;
 	psmouse->reconnect = elantech_reconnect;
+	psmouse->fast_reconnect = NULL;
 	psmouse->pktsize = info->hw_version > 1 ? 6 : 4;
 
 	return 0;
-- 
2.42.0.582.g8ccd20d70d-goog