On Sun, Sep 02, 2018 at 08:47:29AM +0100, Marc Zyngier wrote:
On Thu, 30 Aug 2018 19:01:16 +0100, Sasha Levin Alexander.Levin@microsoft.com wrote:
From: Marc Zyngier marc.zyngier@arm.com
[ Upstream commit 3fc7c5c0cff3150e471f5fd12f59971c6d2c6513 ]
pm_runtime_get_if_in_use can fail: either PM has been disabled altogether (-EINVAL), or the device hasn't been enabled yet (0). Sadly, the Rockchip IOMMU driver tends to conflate the two things by considering a non-zero return value as successful.
This has the consequence of hiding other bugs, so let's handle this case throughout the driver, with a WARN_ON_ONCE so that we can try and work out what happened.
Fixes: 0f181d3cf7d98 ("iommu/rockchip: Add runtime PM support") Reviewed-by: Heiko Stuebner heiko@sntech.de Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Olof Johansson olof@lixom.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com
Picking this patch on its own feels like a bad idea if CONFIG_PM is not selected. Consider picking up 7db7a8f5638a and d1558dfd9f22 which guarantee that things won't break.
Grabbed those 2 as well, thanks!