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[PATCH v4 2/6] bus: mhi: host: pci_generic: Read SUBSYSTEM_VENDOR_ID for VF's to check status

Vivek.Pernamitta@quicinc.com posted 6 patches 2 weeks, 6 days ago
[PATCH v4 2/6] bus: mhi: host: pci_generic: Read SUBSYSTEM_VENDOR_ID for VF's to check status
Posted by Vivek.Pernamitta@quicinc.com 2 weeks, 6 days ago 
From: Vivek Pernamitta <quic_vpernami@quicinc.com>

In SR-IOV enabled devices, reading the VF DEVICE/VENDOR ID register
returns `FFFFh`, as specified in section 3.4.1.1 of the PCIe SR-IOV spec.
To accurately determine device activity, read the PCIe VENDOR_ID of
the Physical Function (PF) instead.
Health check monitoring for Virtual Functions (VFs) has been disabled,
since VFs are not physical functions and lack direct hardware control.
This change prevents unnecessary CPU cycles from being consumed by VF
health checks, which are both unintended and non-functional.

Signed-off-by: Vivek Pernamitta <quic_vpernami@quicinc.com>
Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
---
 drivers/bus/mhi/host/pci_generic.c | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/host/pci_generic.c
index 8a605cb3b8e1e54ef4e699700f3f2660ad5cb093..6fa16975e320212a50e0b68ddb34db5ce711589c 100644
--- a/drivers/bus/mhi/host/pci_generic.c
+++ b/drivers/bus/mhi/host/pci_generic.c
@@ -1082,7 +1082,7 @@ static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl)
 	struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
 	u16 vendor = 0;
 
-	if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor))
+	if (pci_read_config_word(pci_physfn(pdev), PCI_VENDOR_ID, &vendor))
 		return false;
 
 	if (vendor == (u16) ~0 || vendor == 0)
@@ -1193,7 +1193,9 @@ static void mhi_pci_recovery_work(struct work_struct *work)
 
 	dev_warn(&pdev->dev, "device recovery started\n");
 
-	timer_delete(&mhi_pdev->health_check_timer);
+	if (pdev->is_physfn)
+		timer_delete(&mhi_pdev->health_check_timer);
+
 	pm_runtime_forbid(&pdev->dev);
 
 	/* Clean up MHI state */
@@ -1220,7 +1222,10 @@ static void mhi_pci_recovery_work(struct work_struct *work)
 	dev_dbg(&pdev->dev, "Recovery completed\n");
 
 	set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
-	mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
+
+	if (pdev->is_physfn)
+		mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
+
 	return;
 
 err_unprepare:
@@ -1307,7 +1312,9 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	else
 		mhi_cntrl_config = info->config;
 
-	timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
+	/* Initialize health check monitor only for Physical functions */
+	if (pdev->is_physfn)
+		timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
 
 	mhi_cntrl = &mhi_pdev->mhi_cntrl;
 
@@ -1371,7 +1378,8 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
 
 	/* start health check */
-	mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
+	if (pdev->is_physfn)
+		mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
 
 	/* Allow runtime suspend only if both PME from D3Hot and M3 are supported */
 	if (pci_pme_capable(pdev, PCI_D3hot) && !(info->no_m3)) {
@@ -1396,7 +1404,8 @@ static void mhi_pci_remove(struct pci_dev *pdev)
 	struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
 	struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
 
-	timer_delete_sync(&mhi_pdev->health_check_timer);
+	if (pdev->is_physfn)
+		timer_delete_sync(&mhi_pdev->health_check_timer);
 	cancel_work_sync(&mhi_pdev->recovery_work);
 
 	if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
@@ -1424,7 +1433,8 @@ static void mhi_pci_reset_prepare(struct pci_dev *pdev)
 
 	dev_info(&pdev->dev, "reset\n");
 
-	timer_delete(&mhi_pdev->health_check_timer);
+	if (pdev->is_physfn)
+		timer_delete(&mhi_pdev->health_check_timer);
 
 	/* Clean up MHI state */
 	if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
@@ -1469,7 +1479,8 @@ static void mhi_pci_reset_done(struct pci_dev *pdev)
 	}
 
 	set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
-	mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
+	if (pdev->is_physfn)
+		mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
 }
 
 static pci_ers_result_t mhi_pci_error_detected(struct pci_dev *pdev,
@@ -1534,7 +1545,9 @@ static int  __maybe_unused mhi_pci_runtime_suspend(struct device *dev)
 	if (test_and_set_bit(MHI_PCI_DEV_SUSPENDED, &mhi_pdev->status))
 		return 0;
 
-	timer_delete(&mhi_pdev->health_check_timer);
+	if (pdev->is_physfn)
+		timer_delete(&mhi_pdev->health_check_timer);
+
 	cancel_work_sync(&mhi_pdev->recovery_work);
 
 	if (!test_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status) ||
@@ -1585,7 +1598,8 @@ static int __maybe_unused mhi_pci_runtime_resume(struct device *dev)
 	}
 
 	/* Resume health check */
-	mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
+	if (pdev->is_physfn)
+		mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
 
 	/* It can be a remote wakeup (no mhi runtime_get), update access time */
 	pm_runtime_mark_last_busy(dev);

-- 
2.34.1
Re: [PATCH v4 2/6] bus: mhi: host: pci_generic: Read SUBSYSTEM_VENDOR_ID for VF's to check status
Posted by Krishna Chaitanya Chundru 2 weeks, 3 days ago 

On 9/12/2025 6:18 PM, Vivek.Pernamitta@quicinc.com wrote:
> From: Vivek Pernamitta <quic_vpernami@quicinc.com>
> 
> In SR-IOV enabled devices, reading the VF DEVICE/VENDOR ID register
> returns `FFFFh`, as specified in section 3.4.1.1 of the PCIe SR-IOV spec.
> To accurately determine device activity, read the PCIe VENDOR_ID of
> the Physical Function (PF) insteadcommit text and subject needs to be modified to reflect new changes

> Health check monitoring for Virtual Functions (VFs) has been disabled,
> since VFs are not physical functions and lack direct hardware control.
> This change prevents unnecessary CPU cycles from being consumed by VF
> health checks, which are both unintended and non-functional.
> 
> Signed-off-by: Vivek Pernamitta <quic_vpernami@quicinc.com>
> Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
> ---
>   drivers/bus/mhi/host/pci_generic.c | 34 ++++++++++++++++++++++++----------
>   1 file changed, 24 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/host/pci_generic.c
> index 8a605cb3b8e1e54ef4e699700f3f2660ad5cb093..6fa16975e320212a50e0b68ddb34db5ce711589c 100644
> --- a/drivers/bus/mhi/host/pci_generic.c
> +++ b/drivers/bus/mhi/host/pci_generic.c
> @@ -1082,7 +1082,7 @@ static bool mhi_pci_is_alive(struct mhi_controller *mhi_cntrl)
>   	struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
>   	u16 vendor = 0;
>   
> -	if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor))
> +	if (pci_read_config_word(pci_physfn(pdev), PCI_VENDOR_ID, &vendor))
As you are invoking only for physical functions pci_physfn is not needed.

- Krishna Chaitanya
>   		return false;
>   
>   	if (vendor == (u16) ~0 || vendor == 0)
> @@ -1193,7 +1193,9 @@ static void mhi_pci_recovery_work(struct work_struct *work)
>   
>   	dev_warn(&pdev->dev, "device recovery started\n");
>   
> -	timer_delete(&mhi_pdev->health_check_timer);
> +	if (pdev->is_physfn)
> +		timer_delete(&mhi_pdev->health_check_timer);
> +
>   	pm_runtime_forbid(&pdev->dev);
>   
>   	/* Clean up MHI state */
> @@ -1220,7 +1222,10 @@ static void mhi_pci_recovery_work(struct work_struct *work)
>   	dev_dbg(&pdev->dev, "Recovery completed\n");
>   
>   	set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
> -	mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
> +
> +	if (pdev->is_physfn)
> +		mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
> +
>   	return;
>   
>   err_unprepare:
> @@ -1307,7 +1312,9 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>   	else
>   		mhi_cntrl_config = info->config;
>   
> -	timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
> +	/* Initialize health check monitor only for Physical functions */
> +	if (pdev->is_physfn)
> +		timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
>   
>   	mhi_cntrl = &mhi_pdev->mhi_cntrl;
>   
> @@ -1371,7 +1378,8 @@ static int mhi_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
>   	set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
>   
>   	/* start health check */
> -	mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
> +	if (pdev->is_physfn)
> +		mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
>   
>   	/* Allow runtime suspend only if both PME from D3Hot and M3 are supported */
>   	if (pci_pme_capable(pdev, PCI_D3hot) && !(info->no_m3)) {
> @@ -1396,7 +1404,8 @@ static void mhi_pci_remove(struct pci_dev *pdev)
>   	struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
>   	struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
>   
> -	timer_delete_sync(&mhi_pdev->health_check_timer);
> +	if (pdev->is_physfn)
> +		timer_delete_sync(&mhi_pdev->health_check_timer);
>   	cancel_work_sync(&mhi_pdev->recovery_work);
>   
>   	if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
> @@ -1424,7 +1433,8 @@ static void mhi_pci_reset_prepare(struct pci_dev *pdev)
>   
>   	dev_info(&pdev->dev, "reset\n");
>   
> -	timer_delete(&mhi_pdev->health_check_timer);
> +	if (pdev->is_physfn)
> +		timer_delete(&mhi_pdev->health_check_timer);
>   
>   	/* Clean up MHI state */
>   	if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
> @@ -1469,7 +1479,8 @@ static void mhi_pci_reset_done(struct pci_dev *pdev)
>   	}
>   
>   	set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
> -	mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
> +	if (pdev->is_physfn)
> +		mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
>   }
>   
>   static pci_ers_result_t mhi_pci_error_detected(struct pci_dev *pdev,
> @@ -1534,7 +1545,9 @@ static int  __maybe_unused mhi_pci_runtime_suspend(struct device *dev)
>   	if (test_and_set_bit(MHI_PCI_DEV_SUSPENDED, &mhi_pdev->status))
>   		return 0;
>   
> -	timer_delete(&mhi_pdev->health_check_timer);
> +	if (pdev->is_physfn)
> +		timer_delete(&mhi_pdev->health_check_timer);
> +
>   	cancel_work_sync(&mhi_pdev->recovery_work);
>   
>   	if (!test_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status) ||
> @@ -1585,7 +1598,8 @@ static int __maybe_unused mhi_pci_runtime_resume(struct device *dev)
>   	}
>   
>   	/* Resume health check */
> -	mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
> +	if (pdev->is_physfn)
> +		mod_timer(&mhi_pdev->health_check_timer, jiffies + HEALTH_CHECK_PERIOD);
>   
>   	/* It can be a remote wakeup (no mhi runtime_get), update access time */
>   	pm_runtime_mark_last_busy(dev);
>
Re: [PATCH v4 2/6] bus: mhi: host: pci_generic: Read SUBSYSTEM_VENDOR_ID for VF's to check status
Posted by Vivek Pernamitta 2 weeks, 3 days ago 

On 9/15/2025 2:22 PM, Krishna Chaitanya Chundru wrote:
> 
> 
> On 9/12/2025 6:18 PM, Vivek.Pernamitta@quicinc.com wrote:
>> From: Vivek Pernamitta <quic_vpernami@quicinc.com>
>>
>> In SR-IOV enabled devices, reading the VF DEVICE/VENDOR ID register
>> returns `FFFFh`, as specified in section 3.4.1.1 of the PCIe SR-IOV spec.
>> To accurately determine device activity, read the PCIe VENDOR_ID of
>> the Physical Function (PF) insteadcommit text and subject needs to be 
>> modified to reflect new changes
> 
>> Health check monitoring for Virtual Functions (VFs) has been disabled,
>> since VFs are not physical functions and lack direct hardware control.
>> This change prevents unnecessary CPU cycles from being consumed by VF
>> health checks, which are both unintended and non-functional.
>>
>> Signed-off-by: Vivek Pernamitta <quic_vpernami@quicinc.com>
>> Reviewed-by: Krishna Chaitanya Chundru <krishna.chundru@oss.qualcomm.com>
>> ---
>>   drivers/bus/mhi/host/pci_generic.c | 34 +++++++++++++++++++++++ 
>> +----------
>>   1 file changed, 24 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/ 
>> host/pci_generic.c
>> index 
>> 8a605cb3b8e1e54ef4e699700f3f2660ad5cb093..6fa16975e320212a50e0b68ddb34db5ce711589c 100644
>> --- a/drivers/bus/mhi/host/pci_generic.c
>> +++ b/drivers/bus/mhi/host/pci_generic.c
>> @@ -1082,7 +1082,7 @@ static bool mhi_pci_is_alive(struct 
>> mhi_controller *mhi_cntrl)
>>       struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
>>       u16 vendor = 0;
>> -    if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor))
>> +    if (pci_read_config_word(pci_physfn(pdev), PCI_VENDOR_ID, &vendor))
> As you are invoking only for physical functions pci_physfn is not needed.
> 
> - Krishna Chaitanya
pci_physfn(pdev) was intentionally kept as this can be called for VF's
in error handle path. >>           return false;
>>       if (vendor == (u16) ~0 || vendor == 0)
>> @@ -1193,7 +1193,9 @@ static void mhi_pci_recovery_work(struct 
>> work_struct *work)
>>       dev_warn(&pdev->dev, "device recovery started\n");
>> -    timer_delete(&mhi_pdev->health_check_timer);
>> +    if (pdev->is_physfn)
>> +        timer_delete(&mhi_pdev->health_check_timer);
>> +
>>       pm_runtime_forbid(&pdev->dev);
>>       /* Clean up MHI state */
>> @@ -1220,7 +1222,10 @@ static void mhi_pci_recovery_work(struct 
>> work_struct *work)
>>       dev_dbg(&pdev->dev, "Recovery completed\n");
>>       set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
>> -    mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>> HEALTH_CHECK_PERIOD);
>> +
>> +    if (pdev->is_physfn)
>> +        mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>> HEALTH_CHECK_PERIOD);
>> +
>>       return;
>>   err_unprepare:
>> @@ -1307,7 +1312,9 @@ static int mhi_pci_probe(struct pci_dev *pdev, 
>> const struct pci_device_id *id)
>>       else
>>           mhi_cntrl_config = info->config;
>> -    timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
>> +    /* Initialize health check monitor only for Physical functions */
>> +    if (pdev->is_physfn)
>> +        timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
>>       mhi_cntrl = &mhi_pdev->mhi_cntrl;
>> @@ -1371,7 +1378,8 @@ static int mhi_pci_probe(struct pci_dev *pdev, 
>> const struct pci_device_id *id)
>>       set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
>>       /* start health check */
>> -    mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>> HEALTH_CHECK_PERIOD);
>> +    if (pdev->is_physfn)
>> +        mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>> HEALTH_CHECK_PERIOD);
>>       /* Allow runtime suspend only if both PME from D3Hot and M3 are 
>> supported */
>>       if (pci_pme_capable(pdev, PCI_D3hot) && !(info->no_m3)) {
>> @@ -1396,7 +1404,8 @@ static void mhi_pci_remove(struct pci_dev *pdev)
>>       struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
>>       struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
>> -    timer_delete_sync(&mhi_pdev->health_check_timer);
>> +    if (pdev->is_physfn)
>> +        timer_delete_sync(&mhi_pdev->health_check_timer);
>>       cancel_work_sync(&mhi_pdev->recovery_work);
>>       if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
>> @@ -1424,7 +1433,8 @@ static void mhi_pci_reset_prepare(struct pci_dev 
>> *pdev)
>>       dev_info(&pdev->dev, "reset\n");
>> -    timer_delete(&mhi_pdev->health_check_timer);
>> +    if (pdev->is_physfn)
>> +        timer_delete(&mhi_pdev->health_check_timer);
>>       /* Clean up MHI state */
>>       if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
>> @@ -1469,7 +1479,8 @@ static void mhi_pci_reset_done(struct pci_dev 
>> *pdev)
>>       }
>>       set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
>> -    mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>> HEALTH_CHECK_PERIOD);
>> +    if (pdev->is_physfn)
>> +        mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>> HEALTH_CHECK_PERIOD);
>>   }
>>   static pci_ers_result_t mhi_pci_error_detected(struct pci_dev *pdev,
>> @@ -1534,7 +1545,9 @@ static int  __maybe_unused 
>> mhi_pci_runtime_suspend(struct device *dev)
>>       if (test_and_set_bit(MHI_PCI_DEV_SUSPENDED, &mhi_pdev->status))
>>           return 0;
>> -    timer_delete(&mhi_pdev->health_check_timer);
>> +    if (pdev->is_physfn)
>> +        timer_delete(&mhi_pdev->health_check_timer);
>> +
>>       cancel_work_sync(&mhi_pdev->recovery_work);
>>       if (!test_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status) ||
>> @@ -1585,7 +1598,8 @@ static int __maybe_unused 
>> mhi_pci_runtime_resume(struct device *dev)
>>       }
>>       /* Resume health check */
>> -    mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>> HEALTH_CHECK_PERIOD);
>> +    if (pdev->is_physfn)
>> +        mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>> HEALTH_CHECK_PERIOD);
>>       /* It can be a remote wakeup (no mhi runtime_get), update access 
>> time */
>>       pm_runtime_mark_last_busy(dev);
>>
Re: [PATCH v4 2/6] bus: mhi: host: pci_generic: Read SUBSYSTEM_VENDOR_ID for VF's to check status
Posted by Krishna Chaitanya Chundru 2 weeks, 3 days ago 

On 9/15/2025 4:19 PM, Vivek Pernamitta wrote:
> 
> 
> On 9/15/2025 2:22 PM, Krishna Chaitanya Chundru wrote:
>>
>>
>> On 9/12/2025 6:18 PM, Vivek.Pernamitta@quicinc.com wrote:
>>> From: Vivek Pernamitta <quic_vpernami@quicinc.com>
>>>
>>> In SR-IOV enabled devices, reading the VF DEVICE/VENDOR ID register
>>> returns `FFFFh`, as specified in section 3.4.1.1 of the PCIe SR-IOV 
>>> spec.
>>> To accurately determine device activity, read the PCIe VENDOR_ID of
>>> the Physical Function (PF) insteadcommit text and subject needs to be 
>>> modified to reflect new changes
>>
>>> Health check monitoring for Virtual Functions (VFs) has been disabled,
>>> since VFs are not physical functions and lack direct hardware control.
>>> This change prevents unnecessary CPU cycles from being consumed by VF
>>> health checks, which are both unintended and non-functional.
>>>
>>> Signed-off-by: Vivek Pernamitta <quic_vpernami@quicinc.com>
>>> Reviewed-by: Krishna Chaitanya Chundru 
>>> <krishna.chundru@oss.qualcomm.com>
>>> ---
>>>   drivers/bus/mhi/host/pci_generic.c | 34 +++++++++++++++++++++++ 
>>> +----------
>>>   1 file changed, 24 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/drivers/bus/mhi/host/pci_generic.c b/drivers/bus/mhi/ 
>>> host/pci_generic.c
>>> index 
>>> 8a605cb3b8e1e54ef4e699700f3f2660ad5cb093..6fa16975e320212a50e0b68ddb34db5ce711589c 100644
>>> --- a/drivers/bus/mhi/host/pci_generic.c
>>> +++ b/drivers/bus/mhi/host/pci_generic.c
>>> @@ -1082,7 +1082,7 @@ static bool mhi_pci_is_alive(struct 
>>> mhi_controller *mhi_cntrl)
>>>       struct pci_dev *pdev = to_pci_dev(mhi_cntrl->cntrl_dev);
>>>       u16 vendor = 0;
>>> -    if (pci_read_config_word(pdev, PCI_VENDOR_ID, &vendor))
>>> +    if (pci_read_config_word(pci_physfn(pdev), PCI_VENDOR_ID, &vendor))
>> As you are invoking only for physical functions pci_physfn is not needed.
>>
>> - Krishna Chaitanya
> pci_physfn(pdev) was intentionally kept as this can be called for VF's
> in error handle path. >>           return false;
can you include that in the commit text.

- Krishna Chaitanya.
>>>       if (vendor == (u16) ~0 || vendor == 0)
>>> @@ -1193,7 +1193,9 @@ static void mhi_pci_recovery_work(struct 
>>> work_struct *work)
>>>       dev_warn(&pdev->dev, "device recovery started\n");
>>> -    timer_delete(&mhi_pdev->health_check_timer);
>>> +    if (pdev->is_physfn)
>>> +        timer_delete(&mhi_pdev->health_check_timer);
>>> +
>>>       pm_runtime_forbid(&pdev->dev);
>>>       /* Clean up MHI state */
>>> @@ -1220,7 +1222,10 @@ static void mhi_pci_recovery_work(struct 
>>> work_struct *work)
>>>       dev_dbg(&pdev->dev, "Recovery completed\n");
>>>       set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
>>> -    mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>>> HEALTH_CHECK_PERIOD);
>>> +
>>> +    if (pdev->is_physfn)
>>> +        mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>>> HEALTH_CHECK_PERIOD);
>>> +
>>>       return;
>>>   err_unprepare:
>>> @@ -1307,7 +1312,9 @@ static int mhi_pci_probe(struct pci_dev *pdev, 
>>> const struct pci_device_id *id)
>>>       else
>>>           mhi_cntrl_config = info->config;
>>> -    timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
>>> +    /* Initialize health check monitor only for Physical functions */
>>> +    if (pdev->is_physfn)
>>> +        timer_setup(&mhi_pdev->health_check_timer, health_check, 0);
>>>       mhi_cntrl = &mhi_pdev->mhi_cntrl;
>>> @@ -1371,7 +1378,8 @@ static int mhi_pci_probe(struct pci_dev *pdev, 
>>> const struct pci_device_id *id)
>>>       set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
>>>       /* start health check */
>>> -    mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>>> HEALTH_CHECK_PERIOD);
>>> +    if (pdev->is_physfn)
>>> +        mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>>> HEALTH_CHECK_PERIOD);
>>>       /* Allow runtime suspend only if both PME from D3Hot and M3 are 
>>> supported */
>>>       if (pci_pme_capable(pdev, PCI_D3hot) && !(info->no_m3)) {
>>> @@ -1396,7 +1404,8 @@ static void mhi_pci_remove(struct pci_dev *pdev)
>>>       struct mhi_pci_device *mhi_pdev = pci_get_drvdata(pdev);
>>>       struct mhi_controller *mhi_cntrl = &mhi_pdev->mhi_cntrl;
>>> -    timer_delete_sync(&mhi_pdev->health_check_timer);
>>> +    if (pdev->is_physfn)
>>> +        timer_delete_sync(&mhi_pdev->health_check_timer);
>>>       cancel_work_sync(&mhi_pdev->recovery_work);
>>>       if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
>>> @@ -1424,7 +1433,8 @@ static void mhi_pci_reset_prepare(struct 
>>> pci_dev *pdev)
>>>       dev_info(&pdev->dev, "reset\n");
>>> -    timer_delete(&mhi_pdev->health_check_timer);
>>> +    if (pdev->is_physfn)
>>> +        timer_delete(&mhi_pdev->health_check_timer);
>>>       /* Clean up MHI state */
>>>       if (test_and_clear_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status)) {
>>> @@ -1469,7 +1479,8 @@ static void mhi_pci_reset_done(struct pci_dev 
>>> *pdev)
>>>       }
>>>       set_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status);
>>> -    mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>>> HEALTH_CHECK_PERIOD);
>>> +    if (pdev->is_physfn)
>>> +        mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>>> HEALTH_CHECK_PERIOD);
>>>   }
>>>   static pci_ers_result_t mhi_pci_error_detected(struct pci_dev *pdev,
>>> @@ -1534,7 +1545,9 @@ static int  __maybe_unused 
>>> mhi_pci_runtime_suspend(struct device *dev)
>>>       if (test_and_set_bit(MHI_PCI_DEV_SUSPENDED, &mhi_pdev->status))
>>>           return 0;
>>> -    timer_delete(&mhi_pdev->health_check_timer);
>>> +    if (pdev->is_physfn)
>>> +        timer_delete(&mhi_pdev->health_check_timer);
>>> +
>>>       cancel_work_sync(&mhi_pdev->recovery_work);
>>>       if (!test_bit(MHI_PCI_DEV_STARTED, &mhi_pdev->status) ||
>>> @@ -1585,7 +1598,8 @@ static int __maybe_unused 
>>> mhi_pci_runtime_resume(struct device *dev)
>>>       }
>>>       /* Resume health check */
>>> -    mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>>> HEALTH_CHECK_PERIOD);
>>> +    if (pdev->is_physfn)
>>> +        mod_timer(&mhi_pdev->health_check_timer, jiffies + 
>>> HEALTH_CHECK_PERIOD);
>>>       /* It can be a remote wakeup (no mhi runtime_get), update 
>>> access time */
>>>       pm_runtime_mark_last_busy(dev);
>>>
>

Patchew 2.1-devel-b67e4c2

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