Thread (30 messages) 30 messages, 5 authors, 2016-02-22
STALE3752d

[PATCH 2/7] i2c: omap: Fix PM regression with deferred probe for pm_runtime_reinit

From: Wolfram Sang <hidden>
Date: 2016-02-12 18:43:36
Also in: linux-i2c, linux-mmc, linux-omap, linux-serial, linux-spi

On Wed, Feb 10, 2016 at 03:02:45PM -0800, Tony Lindgren wrote:
Commit 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
error and driver unbind") introduced pm_runtime_reinit() that is used
to reinitialize PM runtime after -EPROBE_DEFER. This allows shutting
down the device after a failed probe.

However, for drivers using pm_runtime_use_autosuspend() this can cause
a state where suspend callback is never called after -EPROBE_DEFER.
On the following device driver probe, hardware state is different from
the PM runtime state causing omap_device to produce the following
error:

omap_device_enable() called from invalid state 1

And with omap_device and omap hardware being picky for PM, this will
block any deeper idle states in hardware.

The solution is to fix the drivers to follow the PM runtime documentation:

1. For sections of code that needs the device disabled, use
   pm_runtime_put_sync_suspend() if pm_runtime_set_autosuspend() has
   been set.

2. For driver exit code, use pm_runtime_dont_use_autosuspend() before
   pm_runtime_put_sync() if pm_runtime_use_autosuspend() has been
   set.

Fixes: 5de85b9d57ab ("PM / runtime: Re-init runtime PM states at probe
error and driver unbind")
Cc: linux-i2c at vger.kernel.org
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Ulf Hansson <redacted>
Cc: Tero Kristo <redacted>
Cc: Wolfram Sang <redacted>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Applied to for-current, thanks!

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