[lkml]   [2018]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v1] i2c: tegra: Remove suspend-resume
On Mon, May 14, 2018 at 12:13:47AM +0300, Dmitry Osipenko wrote:
> Nothing prevents I2C clients to access I2C while Tegra's driver is being
> suspended, this results in -EBUSY error returned to the clients and that
> may have unfortunate consequences. In particular this causes problems
> for the TPS6586x MFD driver which emits hundreds of "failed to read
> interrupt status" error messages on resume from suspend. This happens if
> TPS6586X is used to wake system from suspend by the expired RTC alarm
> timer because TPS6586X is an I2C device driver and its IRQ handler reads
> the status register while Tegra's I2C driver is suspended, i.e. just after
> kernel enabled IRQ's during of resume-from-suspend process.
> Note that the removed tegra_i2c_resume() invoked tegra_i2c_init() which
> performs HW reset. That seems was also not entirely correct because moving
> tegra_i2c_resume to an earlier stage of resume-from-suspend process causes
> I2C transfer to fail in the case of TPS6586X. It is fine to remove the
> HW-reinitialization for now because it should be only needed in a case of
> using lowest power-mode during suspend, which upstream kernel doesn't
> support.
> Signed-off-by: Dmitry Osipenko <>
> Cc: <>

Applied to for-next, thanks!

[unhandled content-type:application/pgp-signature]
 \ /
  Last update: 2018-05-30 22:19    [W:0.145 / U:0.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site