| Message ID | 20230608210404.722123-1-jefferymiller@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] Input: synaptics-rmi4 - retry reading SMBus version on resume | expand |
Hi Jeffery, On Thu, Jun 08, 2023 at 09:04:00PM +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. > > Add a 30ms delay and retry in the ENXIO case to ensure 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 30ms delay was chosen based on the linux-input message: > Link: https://lore.kernel.org/all/BYAPR03MB47572F2C65E52ED673238D41B2439@BYAPR03MB4757.namprd03.prod.outlook.com/ I do not quite like putting these retries in RMI code. I wonder if we should not move the delay into psmouse_smbus_reconnect(): if (smbdev->need_deactivate) { psmouse_deactivate(psmouse); /* Give the device time to switch to SMBus mode */ msleep(30); } or even factor it out into psmouse_activate_smbus_mode() and call it from psmouse_smbus_reconnect() as well as psmouse_smbus_init(). Thanks. or even factor it out into psmouse_activate_smbus_mode() and call it from psmouse_smbus_reconnect() as well as psmouse_smbus_init(). Thanks.
diff --git a/drivers/input/rmi4/rmi_smbus.c b/drivers/input/rmi4/rmi_smbus.c index 4bf0e1df6a4a..b6d90c92e8a2 100644 --- a/drivers/input/rmi4/rmi_smbus.c +++ b/drivers/input/rmi4/rmi_smbus.c @@ -45,13 +45,25 @@ static int rmi_smb_get_version(struct rmi_smb_xport *rmi_smb) int retval; /* Check if for SMBus new version device by reading version byte. */ - retval = i2c_smbus_read_byte_data(client, SMB_PROTOCOL_VERSION_ADDRESS); - if (retval < 0) { + for (int i = 0; i < 2; i++) { + if (i > 0) { + dev_warn(&client->dev, "sleeping to retry getting the SMBus version number\n"); + fsleep(30000); + } + retval = i2c_smbus_read_byte_data(client, + SMB_PROTOCOL_VERSION_ADDRESS); + if (retval >= 0) + return retval + 1; + dev_err(&client->dev, "failed to get SMBus version number!\n"); - return retval; + /* There can be a delay on resume where the read returns + * -ENXIO. Retry to allow additional time for the read + * to become responsive. + */ + if (retval != -ENXIO) + break; } - - return retval + 1; + return retval; } /* SMB block write - wrapper over ic2_smb_write_block */
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. Add a 30ms delay and retry in the ENXIO case to ensure 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 30ms delay was chosen based on the linux-input message: Link: https://lore.kernel.org/all/BYAPR03MB47572F2C65E52ED673238D41B2439@BYAPR03MB4757.namprd03.prod.outlook.com/ 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 41351 usecs ``` Signed-off-by: Jeffery Miller <jefferymiller@google.com> --- 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@google.com/ 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. If the rmi_smb_probe device_disable_async_suspend patch is applied it will also avoid this issue. However the time between the psmouse_deactivate call for serio_resume and rmi_smb_resume was over 60ms on my test machine. This would naturally be long enough to avoid this particular delay. Changes in v3: - Tagged mail message Link to resolve checkpatch warning. Changes in v2: - Changed to a single retry of 30ms based on previous feedback. drivers/input/rmi4/rmi_smbus.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-)