Re: [PATCH v3] HID: i2c-hid: Fix suspend/resume when already runtime suspended

[Jiri Kosina]

On Tue, 8 Mar 2016, Dmitry Torokhov wrote:

> On ACPI-based systems ACPI power domain code runtime resumes device before
> calling suspend method, which ensures that i2c-hid suspend code starts with
> device not in low-power state and with interrupts enabled.
> 
> On other systems, especially if device is not a part of any power domain,
> we may end up calling driver's system-level suspend routine while the
> device is runtime-suspended (with controller in presumably low power state
> and interrupts disabled). This will result in interrupts being essentially
> disabled twice, and we will only re-enable them after both system resume
> and runtime resume methods complete. Unfortunately i2c_hid_resume() calls
> i2c_hid_hwreset() and that only works properly if interrupts are enabled.
> 
> Also if device is runtime-suspended driver's suspend code may fail if it
> tries to issue I/O requests.
> 
> Let's fix it by runtime-resuming the device if we need to run HID driver's
> suspend code and also disabling interrupts only if device is not already
> runtime-suspended. Also on resume we mark the device as running at full
> power (since that is what resetting will do to it).
> 
> Signed-off-by: Doug Anderson <dianders@xxxxxxxxxxxx>
> Signed-off-by: Dmitry Torokhov <dtor@xxxxxxxxxxxx>

Applied to for-4.6/i2c-hid, thanks.

On Wed, 9 Mar 2016, Benjamin Tissoires wrote:

> Well, I have completely no way of testing this myself, and I blindly
> trust Mika, Dmitry and the others for doing the right thing :).

Welcome to the wonderful world of linux kernel maintainers! :p

Thanks,

-- 
Jiri Kosina
SUSE Labs