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 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
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 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 ---
Changes in v2:
* Switched to a new API "mhi_pm_resume_force()" instead of the "force" flag as suggested by Greg. The "force" flag is now used inside the API.
Greg: I'm sending this patch directly to you so that you can apply it to char-misc once we get an ACK from Kalle.
drivers/bus/mhi/core/pm.c | 21 ++++++++++++++++++--- drivers/net/wireless/ath/ath11k/mhi.c | 6 +++++- include/linux/mhi.h | 13 +++++++++++++ 3 files changed, 36 insertions(+), 4 deletions(-)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index fb99e3727155..547e6e769546 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) +static 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) { @@ -940,8 +944,19 @@ int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
return 0; } + +int mhi_pm_resume(struct mhi_controller *mhi_cntrl) +{ + return __mhi_pm_resume(mhi_cntrl, false); +} EXPORT_SYMBOL_GPL(mhi_pm_resume);
+int mhi_pm_resume_force(struct mhi_controller *mhi_cntrl) +{ + return __mhi_pm_resume(mhi_cntrl, true); +} +EXPORT_SYMBOL_GPL(mhi_pm_resume_force); + int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl) { int ret; diff --git a/drivers/net/wireless/ath/ath11k/mhi.c b/drivers/net/wireless/ath/ath11k/mhi.c index 26c7ae242db6..49c0b1ad40a0 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_force(ab_pci->mhi_ctrl); break; case ATH11K_MHI_TRIGGER_RDDM: ret = mhi_force_rddm_mode(ab_pci->mhi_ctrl); diff --git a/include/linux/mhi.h b/include/linux/mhi.h index 723985879035..a5cc4cdf9cc8 100644 --- a/include/linux/mhi.h +++ b/include/linux/mhi.h @@ -663,6 +663,19 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl); */ int mhi_pm_resume(struct mhi_controller *mhi_cntrl);
+/** + * mhi_pm_resume_force - Force resume MHI from suspended state + * @mhi_cntrl: MHI controller + * + * Resume the device irrespective of its MHI state. As per the MHI spec, devices + * has to be in M3 state during resume. But some devices seem to be in a + * different MHI state other than M3 but they continue working fine if allowed. + * This API is intented to be used for such devices. + * + * Return: 0 if the resume succeeds, a negative error code otherwise + */ +int mhi_pm_resume_force(struct mhi_controller *mhi_cntrl); + /** * mhi_download_rddm_image - Download ramdump image from device for * debugging purpose.