bus: mhi: Early MHI resume failure in non M3 state

MHI suspend/resume are symmetric and balanced procedures. If device is
not in M3 state on a resume, that means something happened behind our
back. In this case resume is aborted and error reported, to let the
controller handle the situation.

This is mainly requested for system wide suspend-resume operation in
PCI context which may lead to power-down/reset of the controller which
will then lose its MHI context. In such cases, PCI driver is supposed
to recover and reinitialize the device.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Reviewed-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1614960841-20233-1-git-send-email-loic.poulain@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
This commit is contained in:
Loic Poulain 2021-03-05 17:14:01 +01:00 committed by Manivannan Sadhasivam
parent 8de5ad9941
commit 020d3b26c0
1 changed files with 3 additions and 0 deletions

View File

@ -880,6 +880,9 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))
return -EIO;
if (mhi_get_mhi_state(mhi_cntrl) != MHI_STATE_M3)
return -EINVAL;
/* Notify clients about exiting LPM */
list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) {
mutex_lock(&itr->mutex);