lkml.org 
[lkml]   [2023]   [Jul]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4] Input: psmouse - add delay when deactivating for SMBus mode
On Wed, Jul 26, 2023 at 02:52:48AM +0000, Jeffery Miller wrote:
> There is a period of time between the psmouse deactivate and the
> ability to communicate with the SMBus companion. Insert a
> sleep after the deactivate to account for the delay and ensure
> the SMBus companion is responsive.
>
> Attempting to read from the SMBus companion too quickly was causing
> the touchpad on machines with an i801_smbus companion to stop working
> after a sleep/resume cycle.
>
> On resume the rmi4_smbus would fail with errors reading the SMBus version
> number:
> ```
> [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_f01 rmi4-00.fn01: Failed to restore normal operation: -6.
> rmi4_f01 rmi4-00.fn01: Resume failed with code -6.
> rmi4_physical rmi4-00: Failed to suspend functions: -6
> rmi4_smbus 0-002c: Failed to resume device: -6
> ```
> In this case the rmi_smb_get_version fails with -ENXIO if it happens too
> soon after the preceding serio_resume -> psmouse_deactivate call.
>
> On boot this issue could cause the touchpad to stay in the limited PS/2
> mode. This only reproduced in 1 in 10 boots on the Lenovo T440p.
> Failures in the log on boot would show up as:
> ```
> psmouse serio1: synaptics: Trying to set up SMBus access
> [122] i2c_i801:i801_check_post:437: i801_smbus 0000:00:1f.3: No response
> psmouse serio1: synaptics: SMbus companion is not ready yet
> ```
>
> Experimentation on the Lenovo T440p showed that a delay of 7-12ms on
> resume allowed the companion to respond.
>
> The 30ms delay in this patch was chosen based on the linux-input message:
> Link: https://lore.kernel.org/all/BYAPR03MB47572F2C65E52ED673238D41B2439@BYAPR03MB4757.namprd03.prod.outlook.com/
>
> Signed-off-by: Jeffery Miller <jefferymiller@google.com>

Applied, thank you.

--
Dmitry

\
 
 \ /
  Last update: 2023-07-26 07:14    [W:0.022 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site