bus: mhi: core: Add support for forced PM resume
authorLoic Poulain <loic.poulain@linaro.org>
Thu, 9 Dec 2021 13:16:33 +0000 (18:46 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 14 Dec 2021 09:57:22 +0000 (10:57 +0100)
commit47b355f25b55c98c63ed7346faa3e1613c895f7e
tree2a52074a9ef92ef18b7eb2af81dd7ab93ee65a24
parent7f4b37c7a692dc9e80cc1f37bb903c759a3ed767
bus: mhi: core: Add support for forced PM resume

commit cab2d3fd6866e089b5c50db09dece131f85bfebd upstream.

For whatever reason, some devices like QCA6390, WCN6855 using ath11k
are not in M3 state during PM resume, but still functional. The
mhi_pm_resume should then not fail in those cases, and let the higher
level device specific stack continue resuming process.

Add an API mhi_pm_resume_force(), to force resuming irrespective of the
current MHI state. This fixes a regression with non functional ath11k WiFi
after suspend/resume cycle on some machines.

Bug report: https://bugzilla.kernel.org/show_bug.cgi?id=214179

Link: https://lore.kernel.org/regressions/871r5p0x2u.fsf@codeaurora.org/
Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state")
Cc: stable@vger.kernel.org #5.13
Reported-by: Kalle Valo <kvalo@codeaurora.org>
Reported-by: Pengyu Ma <mapengyu@gmail.com>
Tested-by: Kalle Valo <kvalo@kernel.org>
Acked-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
[mani: Switched to API, added bug report, reported-by tags and CCed stable]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20211209131633.4168-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/bus/mhi/core/pm.c
drivers/net/wireless/ath/ath11k/mhi.c
include/linux/mhi.h