tree a394c727a6f7e8854f3e24d17efd5dfbbfa86878
parent 56fc3de955b5000a4a0d884774c897e7ba5ba8f0
author Jon Hunter <jonathanh@nvidia.com> 1558022032 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1580289865 +0100

dmaengine: tegra210-adma: Fix crash during probe

[ Upstream commit b53611fb1ce9b1786bd18205473e0c1d6bfa8934 ]

Commit f33e7bb3eb92 ("dmaengine: tegra210-adma: restore channel status")
added support to save and restore the DMA channel registers when runtime
suspending the ADMA. This change is causing the kernel to crash when
probing the ADMA, if the device is probed deferred when looking up the
channel interrupts. The crash occurs because not all of the channel base
addresses have been setup at this point and in the clean-up path of the
probe, pm_runtime_suspend() is called invoking its callback which
expects all the channel base addresses to be initialised.

Although this could be fixed by simply checking for a NULL address, on
further review of the driver it seems more appropriate that we only call
pm_runtime_get_sync() after all the channel interrupts and base
addresses have been configured. Therefore, fix this crash by moving the
calls to pm_runtime_enable(), pm_runtime_get_sync() and
tegra_adma_init() after the DMA channels have been initialised.

Fixes: f33e7bb3eb92 ("dmaengine: tegra210-adma: restore channel status")

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>