4.19-stable review patch. If anyone has any objections, please let me know.
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From: Jeffery Miller jefferymiller@google.com
commit e2cb5cc822b6c9ee72c56ce1d81671b22c05406a upstream.
When the SMBus connection is attempted psmouse_smbus_init() sets the fast_reconnect pointer to psmouse_smbus_reconnecti(). If SMBus initialization fails, elantech_setup_ps2() and synaptics_init_ps2() will fallback to PS/2 mode, replacing the psmouse private data. This can cause issues on resume, since psmouse_smbus_reconnect() expects to find an instance of struct psmouse_smbus_dev in psmouse->private.
The issue was uncovered when in 92e24e0e57f7 ("Input: psmouse - add delay when deactivating for SMBus mode") psmouse_smbus_reconnect() started attempting to use more of the data structure. The commit was since reverted, not because it was at fault, but because there was found a better way of doing what it was attempting to do.
Fix the problem by resetting the fast_reconnect pointer in psmouse structure in elantech_setup_ps2() and synaptics_init_ps2() when the PS/2 mode is used.
Reported-by: Thorsten Leemhuis linux@leemhuis.info Tested-by: Thorsten Leemhuis linux@leemhuis.info Signed-off-by: Jeffery Miller jefferymiller@google.com Fixes: bf232e460a35 ("Input: psmouse-smbus - allow to control psmouse_deactivate") Link: https://lore.kernel.org/r/20231005002249.554877-1-jefferymiller@google.com Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/input/mouse/elantech.c | 1 + drivers/input/mouse/synaptics.c | 1 + 2 files changed, 2 insertions(+)
--- a/drivers/input/mouse/elantech.c +++ b/drivers/input/mouse/elantech.c @@ -1996,6 +1996,7 @@ static int elantech_setup_ps2(struct psm 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; --- a/drivers/input/mouse/synaptics.c +++ b/drivers/input/mouse/synaptics.c @@ -1620,6 +1620,7 @@ static int synaptics_init_ps2(struct psm psmouse->set_rate = synaptics_set_rate; psmouse->disconnect = synaptics_disconnect; psmouse->reconnect = synaptics_reconnect; + psmouse->fast_reconnect = NULL; psmouse->cleanup = synaptics_reset; /* Synaptics can usually stay in sync without extra help */ psmouse->resync_time = 0;