On Wed, May 10, 2023 at 07:27:22PM +0000, Jeffery Miller wrote: > On resume there can be a period of time after the > preceding serio_resume -> psmouse_deactivate call > where calls to rmi_smb_get_version fail with > -ENXIO. > > The call path in rmi_smb_resume is rmi_smb_resume -> rmi_smb_reset -> > rmi_smb_enable_smbus_mode -> rmi_smb_get_version where > this failure would occur. > > Adding a retry loop ensures that after rmi_smb_reset returns > the following rmi_driver_resume calls in rmi_smbus_resume can > succeed. > > This behavior was seen on a Lenovo T440p machine that required > a delay of approximately 7-12ms. > The retry limit of 5 is chosen to be larger than > this observed delay. > > With this patch the trimmed resume logs look similar to: > ``` > psmouse serio1: PM: calling serio_resume+0x0/0x8c @ 5399, parent: i8042 > [5399] libps2:__ps2_command:316: psmouse serio1: f5 [] - 0/00000000 [] > psmouse serio1: PM: serio_resume+0x0/0x8c returned 0 after 3259 usecs > ... > rmi4_smbus 0-002c: PM: calling rmi_smb_resume ... @ 5454, parent: i2c-0 > ... > [5454] i2c_i801:i801_check_post:414: i801_smbus 0000:00:1f.3: No response > smbus_result: i2c-0 a=02c f=0000 c=fd BYTE_DATA rd res=-6 > rmi4_smbus 0-002c: failed to get SMBus version number! > rmi4_smbus 0-002c: sleeping to retry getting the SMBus version number > ... > rmi4_smbus 0-002c: PM: rmi_smb_resume ... returned 0 after 21351 usecs > ``` > > Signed-off-by: Jeffery Miller <jefferymiller@xxxxxxxxxx> > --- > > Early boot dmesg include: > ``` > rmi4_smbus 0-002c: registering SMbus-connected sensor > rmi4_f01 rmi4-00.fn01: found RMI device, manufacturer: Synaptics, product: TM2722-001, fw id: 0 > ``` > > The resume order looks correct. The `psmouse serio1` resume returns > before the rmi_smb_resume is called showing the patch from > https://lore.kernel.org/all/89456fcd-a113-4c82-4b10-a9bcaefac68f@xxxxxxxxxx/ > is applied and working for that ordering. > > I attempted to try to rule out some interaction between the concurrent > input resume calls for other i8042 devices. > Adding a 7ms delay after psmouse_deactivate which is called in the > preceding psmouse serio1 serio_resume function also allows > this version call to succeed. I am not really fond of adding random repeats in the code base. Andrew, do you know if the Synaptics device needs certain delay when switching to SMbus mode? Thanks. -- Dmitry
