diff mbox series

bus: mhi: core: Add support for forced PM resume

Message ID 20211206161059.107007-1-manivannan.sadhasivam@linaro.org
State Superseded
Headers show
Series bus: mhi: core: Add support for forced PM resume | expand

Commit Message

Manivannan Sadhasivam Dec. 6, 2021, 4:10 p.m. UTC
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

Cc: stable@vger.kernel.org #5.13
Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state")
Reported-by: Kalle Valo <kvalo@codeaurora.org>
Reported-by: Pengyu Ma <mapengyu@gmail.com>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
[mani: Added comment, bug report, added reported-by tags and CCed stable]
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(-)

Comments

Hemant Kumar Dec. 7, 2021, 11:41 p.m. UTC | #1
Hi Mani,

On 12/6/2021 8:10 AM, 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
> 
> Cc: stable@vger.kernel.org #5.13
> Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state")
> Reported-by: Kalle Valo <kvalo@codeaurora.org>
> Reported-by: Pengyu Ma <mapengyu@gmail.com>
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> [mani: Added comment, bug report, added reported-by tags and CCed stable]
> 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 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
Manivannan Sadhasivam Dec. 8, 2021, 8:30 a.m. UTC | #2
On Tue, Dec 07, 2021 at 03:41:42PM -0800, Hemant Kumar wrote:
> Hi Mani,
> 
> On 12/6/2021 8:10 AM, 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
> > 
> > Cc: stable@vger.kernel.org #5.13
> > Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state")
> > Reported-by: Kalle Valo <kvalo@codeaurora.org>
> > Reported-by: Pengyu Ma <mapengyu@gmail.com>
> > Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> > [mani: Added comment, bug report, added reported-by tags and CCed stable]
> > 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 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?

SYS_ERR state is a valid case while resuming from suspend. The "force" flag is
supposed to be used by controllers that goes to a weird state like RESET. If we
just add check for RESET, then we might get another scenario in future. That's
why the "force" flag made sense to me.

If we want to handle SYS_ERR then we need to check for that before M3 and that
can be done in a separate patch. But since we didn't hit this scenario till now,
let's handle it later if needed.

Thanks,
Mani

> > +		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
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a
> Linux Foundation Collaborative Project
Manivannan Sadhasivam Dec. 8, 2021, 8:42 a.m. UTC | #3
On Mon, Dec 06, 2021 at 09:40:59PM +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
> 
> Cc: stable@vger.kernel.org #5.13
> Fixes: 020d3b26c07a ("bus: mhi: Early MHI resume failure in non M3 state")
> Reported-by: Kalle Valo <kvalo@codeaurora.org>
> Reported-by: Pengyu Ma <mapengyu@gmail.com>
> Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
> [mani: Added comment, bug report, added reported-by tags and CCed stable]
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

Applied to mhi-fixes! Will be submitted for v5.16-rcX.

Thanks,
Mani

> ---
>  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) {
> +		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 9ef41354237c..efd1da66fdf9 100644
> --- a/drivers/bus/mhi/pci_generic.c
> +++ b/drivers/bus/mhi/pci_generic.c
> @@ -959,7 +959,7 @@ 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);
>  		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..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);
>  
>  /**
>   * mhi_download_rddm_image - Download ramdump image from device for
> -- 
> 2.25.1
>
diff mbox series

Patch

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) {
+		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 9ef41354237c..efd1da66fdf9 100644
--- a/drivers/bus/mhi/pci_generic.c
+++ b/drivers/bus/mhi/pci_generic.c
@@ -959,7 +959,7 @@  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);
 		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..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);
 
 /**
  * mhi_download_rddm_image - Download ramdump image from device for