Messages in this thread | | | Date | Wed, 9 Mar 2016 14:04:11 +0200 | From | Mika Westerberg <> | Subject | Re: [PATCH v3] HID: i2c-hid: Fix suspend/resume when already runtime suspended |
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On Tue, Mar 08, 2016 at 03:03:23PM -0800, 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@chromium.org> > Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Tested on a couple of Intel Skylake and Baytrail based systems and power management of I2C connected HID devices still seems to work just fine.
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
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