On Wed, Dec 08, 2021 at 02:27:35PM +0530, Manivannan Sadhasivam wrote:
From: Loic Poulain loic.poulain@linaro.org
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 a new parameter to mhi_pm_resume, to force resuming, whatever the current MHI state is. 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
Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state") Cc: stable@vger.kernel.org #5.13 Link: https://lore.kernel.org/regressions/871r5p0x2u.fsf@codeaurora.org/ 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: Added comment, bug report, reported-by tags and CCed stable] Link: https://lore.kernel.org/r/20211206161059.107007-1-manivannan.sadhasivam@lina... Signed-off-by: Manivannan Sadhasivam manivannan.sadhasivam@linaro.org
drivers/bus/mhi/core/pm.c | 10 +++++++--- drivers/bus/mhi/pci_generic.c | 2 +- drivers/net/wireless/ath/ath11k/mhi.c | 6 +++++- include/linux/mhi.h | 3 ++- 4 files changed, 15 insertions(+), 6 deletions(-)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index fb99e3727155..8a486374d57a 100644 --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -881,7 +881,7 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl) } EXPORT_SYMBOL_GPL(mhi_pm_suspend); -int mhi_pm_resume(struct mhi_controller *mhi_cntrl) +int mhi_pm_resume(struct mhi_controller *mhi_cntrl, bool force) { struct mhi_chan *itr, *tmp; struct device *dev = &mhi_cntrl->mhi_dev->dev; @@ -898,8 +898,12 @@ 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;
- if (mhi_get_mhi_state(mhi_cntrl) != MHI_STATE_M3) {
dev_warn(dev, "Resuming from non M3 state (%s)\n",TO_MHI_STATE_STR(mhi_get_mhi_state(mhi_cntrl)));if (!force)return -EINVAL;- }
/* Notify clients about exiting LPM */ list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) { diff --git a/drivers/bus/mhi/pci_generic.c b/drivers/bus/mhi/pci_generic.c index 4c577a731709..3394819e8115 100644 --- a/drivers/bus/mhi/pci_generic.c +++ b/drivers/bus/mhi/pci_generic.c @@ -962,7 +962,7 @@ static int __maybe_unused mhi_pci_runtime_resume(struct device *dev) return 0; /* Nothing to do at MHI level */ /* Exit M3, transition to M0 state */
- err = mhi_pm_resume(mhi_cntrl);
- err = mhi_pm_resume(mhi_cntrl, false); if (err) { dev_err(&pdev->dev, "failed to resume device: %d\n", err); goto err_recovery;
diff --git a/drivers/net/wireless/ath/ath11k/mhi.c b/drivers/net/wireless/ath/ath11k/mhi.c index 26c7ae242db6..f1f2fa2d690d 100644 --- a/drivers/net/wireless/ath/ath11k/mhi.c +++ b/drivers/net/wireless/ath/ath11k/mhi.c @@ -533,7 +533,11 @@ static int ath11k_mhi_set_state(struct ath11k_pci *ab_pci, ret = mhi_pm_suspend(ab_pci->mhi_ctrl); break; case ATH11K_MHI_RESUME:
ret = mhi_pm_resume(ab_pci->mhi_ctrl);
/* Do force MHI resume as some devices like QCA6390, WCN6855* are not in M3 state but they are functional. So just ignore* the MHI state while resuming.*/ret = mhi_pm_resume(ab_pci->mhi_ctrl, true);diff --git a/include/linux/mhi.h b/include/linux/mhi.h index 723985879035..102303288cee 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -660,8 +660,9 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl); /**
- mhi_pm_resume - Resume MHI from suspended state
- @mhi_cntrl: MHI controller
*/
- @force: Force resuming to M0 irrespective of the device MHI state
-int mhi_pm_resume(struct mhi_controller *mhi_cntrl); +int mhi_pm_resume(struct mhi_controller *mhi_cntrl, bool force);
apis like this are horrid to work with over time.
Why not just have: mhi_pm_resume_force() which then internally can set a flag that does this? That way the driver author does not have to stop every time they see this call and look up exactly what the true/false field means in the function call in their driver.
It also lets you leave alone the existing calls to mhi_pm_suspend() that do not want to "force" anything.
self-documenting code is good, this is not self-documenting at all.
Also, is "force" really what you are doing here? This is a "normal" resume call, which should always work. The "force" option here really is just "ignore the current state of suspend for the device". So perhaps mhi_pm_resume_ignore_current_state() might be better? Or something shorter?
Naming is hard, sorry.
thanks,
greg k-h