We lose even config space access when we power gate the ISP
via the PUNIT. That makes lspci & co. produce gibberish.
To fix that let's try to implement actual runtime pm hooks
and inform the pci core that the device always goes to
D3cold. That will cause the pci core to resume the device
before attempting config space access.
This introduces another annoyance though. We get the
following error every time we try to resume the device:
intel_atomisp2_pm 0000:00:03.0: Refused to change power state, currently in D3
The reason being that the pci core tries to put the device
back into D0 via the standard PCI PM mechanism before
calling the driver resume hook. To fix this properly
we'd need to infiltrate the platform pm hooks (could
turn ugly real fast), or use pm domains (which don't
seem to exist on x86), or some extra early resume
hook for the driver (which doesn't exist either).
So maybe we just choose to live with the error?
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
If the ISP is exposed as a PCI device VLV machines need the
same treatment as CHV machines to power gate the ISP. Otherwise
s0ix will not work.
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Darren Hart <dvhart@infradead.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
The Image Signal Processor found on Cherry Trail devices is brought up in
D0 state on devices which have camera sensors attached to it. The ISP will
not enter D3 state again without some massaging of its registers beforehand
and the ISP not being in D3 state blocks the SoC from entering S0ix modes.
There was a driver for the ISP in drivers/staging but that got removed
again because it never worked. It does not seem likely that a real
driver for the ISP will be added to the mainline kernel anytime soon.
This commit adds a dummy driver which contains the necessary magic from
the staging driver to powerdown the ISP, so that Cherry Trail devices where
the ISP is used will properly use S0ix modes when suspended.
Together with other recent S0ix related fixes this allows S0ix modes to
be entered on e.g. a Chuwi Hi8 Pro and a HP x2 210.
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=196915
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
