Hi Mani,
On 12/6/2021 8:10 AM, Manivannan Sadhasivam wrote:
From: Loic Poulain <loic.poulain@xxxxxxxxxx>
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
Cc: stable@xxxxxxxxxxxxxxx #5.13
Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state")
Reported-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Reported-by: Pengyu Ma <mapengyu@xxxxxxxxx>
Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
[mani: Added comment, bug report, added reported-by tags and CCed stable]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
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 7464f5d09973..4ddd266e042e 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) {
in case if mhi_get_mhi_state(mhi_cntrl) returns SYS_ERR (assuming while
doing this check SYS_ERR is set) do we still want to continue pm resume
when force is true? Just want to make sure SYS_ERR handling with and
without this change remains the same or atleast does not cause any
regression with this change. or if we need to continue pm resume only
for MHI_STATE_RESET when MHI_STATE_M3 is not set?
+ dev_warn(dev, "Resuming from non M3 state (%s)\n",
+ TO_MHI_STATE_STR(mhi_get_mhi_state(mhi_cntrl)));
+ if (!force)
+ return -EINVAL;
+ }
[..]
Thanks,
Hemant
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