Re: [PATCH] i2c: Prevent runtime suspend of adapter when Host Notify is required

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tue, Apr 30, 2019 at 05:23:22PM +0300, Jarkko Nikula wrote:
> Multiple users have reported their Synaptics touchpad has stopped
> working between v4.20.1 and v4.20.2 when using SMBus interface.
> 
> The culprit for this appeared to be commit c5eb1190074c ("PCI / PM: Allow
> runtime PM without callback functions") that fixed the runtime PM for
> i2c-i801 SMBus adapter. Those Synaptics touchpad are using i2c-i801
> for SMBus communication and testing showed they are able to get back
> working by preventing the runtime suspend of adapter.
> 
> Normally when i2c-i801 SMBus adapter transmits with the client it resumes
> before operation and autosuspends after.
> 
> However, if client requires SMBus Host Notify protocol, what those
> Synaptics touchpads do, then the host adapter must not go to runtime
> suspend since then it cannot process incoming SMBus Host Notify commands
> the client may send.
> 
> Fix this by keeping I2C/SMBus adapter active in case client requires
> Host Notify.
> 
> Reported-by: Keijo Vaara <ferdasyn@xxxxxxxxxxxxxx>
> Link: https://bugzilla.kernel.org/show_bug.cgi?id=203297
> Fixes: c5eb1190074c ("PCI / PM: Allow runtime PM without callback functions")
> Cc: stable@xxxxxxxxxxxxxxx # v4.20+
> Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>

Applied to for-current-fixed, thanks!

Attachment: signature.asc
Description: PGP signature


[Index of Archives]     [Linux GPIO]     [Linux SPI]     [Linux Hardward Monitoring]     [LM Sensors]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux