[PATCH] usb: dwc3: core: configure PHY before initializing host in dwc3_set_mode

[PATCH] usb: dwc3: core: configure PHY before initializing host in dwc3_set_mode

[Sven Peter]

Usually, first the PHY is set to the correct mode and then the host or
device side of the controller is initialized afterwards. Otherwise a PHY
that's already used has to be reconfigured.
dwc3_core_init_mode() does this correctly for both host and device and
__dwc3_set_mode() does it correctly when switching to device mode.
When setting up host mode however it first initializes xhci and only
then changes the PHY's mode. Let's also do the operations in the correct
order here.

Fixes: 958d1a4c40dd ("usb: dwc3: core: program PHY for proper DRD modes")
Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
 drivers/usb/dwc3/core.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index ad4d644e21a4..759d23d908fa 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -212,14 +212,15 @@ static void __dwc3_set_mode(struct work_struct *work)
 
 	switch (dwc->desired_dr_role) {
 	case DWC3_GCTL_PRTCAP_HOST:
+		if (dwc->usb2_phy)
+			otg_set_vbus(dwc->usb2_phy->otg, true);
+		phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
+		phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
+
 		ret = dwc3_host_init(dwc);
 		if (ret) {
 			dev_err(dwc->dev, "failed to initialize host\n");
 		} else {
-			if (dwc->usb2_phy)
-				otg_set_vbus(dwc->usb2_phy->otg, true);
-			phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
-			phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
 			if (dwc->dis_split_quirk) {
 				reg = dwc3_readl(dwc->regs, DWC3_GUCTL3);
 				reg |= DWC3_GUCTL3_SPLITDISABLE;
-- 
2.25.1

Re: [PATCH] usb: dwc3: core: configure PHY before initializing host in dwc3_set_mode

[Ferry Toth]

Hi Sven,

Op 12-11-2022 om 11:25 schreef Sven Peter:
> Usually, first the PHY is set to the correct mode and then the host or
> device side of the controller is initialized afterwards. Otherwise a PHY
> that's already used has to be reconfigured.
> dwc3_core_init_mode() does this correctly for both host and device and
> __dwc3_set_mode() does it correctly when switching to device mode.
> When setting up host mode however it first initializes xhci and only
> then changes the PHY's mode. Let's also do the operations in the correct
> order here.
> 
> Fixes: 958d1a4c40dd ("usb: dwc3: core: program PHY for proper DRD modes")
> Signed-off-by: Sven Peter <sven@svenpeter.dev>
> ---
>   drivers/usb/dwc3/core.c | 9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index ad4d644e21a4..759d23d908fa 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -212,14 +212,15 @@ static void __dwc3_set_mode(struct work_struct *work)
>   
>   	switch (dwc->desired_dr_role) {
>   	case DWC3_GCTL_PRTCAP_HOST:
> +		if (dwc->usb2_phy)
> +			otg_set_vbus(dwc->usb2_phy->otg, true);
> +		phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
> +		phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
> +
>   		ret = dwc3_host_init(dwc);
>   		if (ret) {
>   			dev_err(dwc->dev, "failed to initialize host\n");
>   		} else {
> -			if (dwc->usb2_phy)
> -				otg_set_vbus(dwc->usb2_phy->otg, true);
> -			phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
> -			phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>   			if (dwc->dis_split_quirk) {
>   				reg = dwc3_readl(dwc->regs, DWC3_GUCTL3);
>   				reg |= DWC3_GUCTL3_SPLITDISABLE;
This patch breaks usb host mode on Intel Merrifield platform. I am 
testing this on top of v6.0 +
* my 2 "usb: dwc3: core: defer probe on ulpi_read_id timeout" patches 
(otherwise tusb1210 will not be probed on this platform)
* Revert "usb: dwc3: disable USB core PHY management" (with/without this 
patch makes no difference)
* usb: dwc3: Do not get extcon device when usb-role-switch is used 
(with/without this patch makes no difference)

ftrace shows tusb1210 is indeed still probed, nevertheless in host mode 
it seems vbus is not powered as my connected smsc95xx based hub is not 
active (seems not plugged).

Flipping the switch to device mode gadgets work fine.

Could it be dwc3_host_init() needs to be called prior to otg_set_vbus()?

Re: [PATCH] usb: dwc3: core: configure PHY before initializing host in dwc3_set_mode

[Sven Peter]

Hi Ferry,

On Sat, Nov 12, 2022, at 23:15, Ferry Toth wrote:
> Hi Sven,
>
> Op 12-11-2022 om 11:25 schreef Sven Peter:
>> Usually, first the PHY is set to the correct mode and then the host or
>> device side of the controller is initialized afterwards. Otherwise a PHY
>> that's already used has to be reconfigured.
>> dwc3_core_init_mode() does this correctly for both host and device and
>> __dwc3_set_mode() does it correctly when switching to device mode.
>> When setting up host mode however it first initializes xhci and only
>> then changes the PHY's mode. Let's also do the operations in the correct
>> order here.
>> 
>> Fixes: 958d1a4c40dd ("usb: dwc3: core: program PHY for proper DRD modes")
>> Signed-off-by: Sven Peter <sven@svenpeter.dev>
>> ---
>>   drivers/usb/dwc3/core.c | 9 +++++----
>>   1 file changed, 5 insertions(+), 4 deletions(-)
>> 
>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>> index ad4d644e21a4..759d23d908fa 100644
>> --- a/drivers/usb/dwc3/core.c
>> +++ b/drivers/usb/dwc3/core.c
>> @@ -212,14 +212,15 @@ static void __dwc3_set_mode(struct work_struct *work)
>>   
>>   	switch (dwc->desired_dr_role) {
>>   	case DWC3_GCTL_PRTCAP_HOST:
>> +		if (dwc->usb2_phy)
>> +			otg_set_vbus(dwc->usb2_phy->otg, true);
>> +		phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
>> +		phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>> +
>>   		ret = dwc3_host_init(dwc);
>>   		if (ret) {
>>   			dev_err(dwc->dev, "failed to initialize host\n");
>>   		} else {
>> -			if (dwc->usb2_phy)
>> -				otg_set_vbus(dwc->usb2_phy->otg, true);
>> -			phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
>> -			phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>>   			if (dwc->dis_split_quirk) {
>>   				reg = dwc3_readl(dwc->regs, DWC3_GUCTL3);
>>   				reg |= DWC3_GUCTL3_SPLITDISABLE;
> This patch breaks usb host mode on Intel Merrifield platform. I am 
> testing this on top of v6.0 +
> * my 2 "usb: dwc3: core: defer probe on ulpi_read_id timeout" patches 
> (otherwise tusb1210 will not be probed on this platform)
> * Revert "usb: dwc3: disable USB core PHY management" (with/without this 
> patch makes no difference)
> * usb: dwc3: Do not get extcon device when usb-role-switch is used 
> (with/without this patch makes no difference)
>
> ftrace shows tusb1210 is indeed still probed, nevertheless in host mode 
> it seems vbus is not powered as my connected smsc95xx based hub is not 
> active (seems not plugged).
>
> Flipping the switch to device mode gadgets work fine.
>
> Could it be dwc3_host_init() needs to be called prior to otg_set_vbus()?

Huh, thanks for testing!

For the platform I'm working on I need to set the phy mode before dwc3_host_init()
and then found the same code further below in dwc3_core_init_mode,

static int dwc3_core_init_mode(struct dwc3 *dwc)
{
[...]
	case USB_DR_MODE_HOST:
		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);

		if (dwc->usb2_phy)
			otg_set_vbus(dwc->usb2_phy->otg, true);
		phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
		phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);

		ret = dwc3_host_init(dwc);
		if (ret)
			return dev_err_probe(dev, ret, "failed to initialize host\n");
		break;
[...]
}

so I'm quite surprised it causes issue in __dwc3_set_mode now.
If otg_set_vbus indeed needs to happen after dwc3_host_init it should probably
also be called afterwards in dwc3_core_init_mode as well.


Best,


Sven

Re: [PATCH] usb: dwc3: core: configure PHY before initializing host in dwc3_set_mode

[Ferry Toth]

Hi,

Op 12-11-2022 om 23:46 schreef Sven Peter:
> Hi Ferry,
> 
> On Sat, Nov 12, 2022, at 23:15, Ferry Toth wrote:
>> Hi Sven,
>>
>> Op 12-11-2022 om 11:25 schreef Sven Peter:
>>> Usually, first the PHY is set to the correct mode and then the host or
>>> device side of the controller is initialized afterwards. Otherwise a PHY
>>> that's already used has to be reconfigured.
>>> dwc3_core_init_mode() does this correctly for both host and device and
>>> __dwc3_set_mode() does it correctly when switching to device mode.
>>> When setting up host mode however it first initializes xhci and only
>>> then changes the PHY's mode. Let's also do the operations in the correct
>>> order here.
>>>
>>> Fixes: 958d1a4c40dd ("usb: dwc3: core: program PHY for proper DRD modes")
>>> Signed-off-by: Sven Peter <sven@svenpeter.dev>
>>> ---
>>>    drivers/usb/dwc3/core.c | 9 +++++----
>>>    1 file changed, 5 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>>> index ad4d644e21a4..759d23d908fa 100644
>>> --- a/drivers/usb/dwc3/core.c
>>> +++ b/drivers/usb/dwc3/core.c
>>> @@ -212,14 +212,15 @@ static void __dwc3_set_mode(struct work_struct *work)
>>>    
>>>    	switch (dwc->desired_dr_role) {
>>>    	case DWC3_GCTL_PRTCAP_HOST:
>>> +		if (dwc->usb2_phy)
>>> +			otg_set_vbus(dwc->usb2_phy->otg, true);
>>> +		phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
>>> +		phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>>> +
>>>    		ret = dwc3_host_init(dwc);
>>>    		if (ret) {
>>>    			dev_err(dwc->dev, "failed to initialize host\n");
>>>    		} else {
>>> -			if (dwc->usb2_phy)
>>> -				otg_set_vbus(dwc->usb2_phy->otg, true);
>>> -			phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
>>> -			phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>>>    			if (dwc->dis_split_quirk) {
>>>    				reg = dwc3_readl(dwc->regs, DWC3_GUCTL3);
>>>    				reg |= DWC3_GUCTL3_SPLITDISABLE;
>> This patch breaks usb host mode on Intel Merrifield platform. I am
>> testing this on top of v6.0 +
>> * my 2 "usb: dwc3: core: defer probe on ulpi_read_id timeout" patches
>> (otherwise tusb1210 will not be probed on this platform)
>> * Revert "usb: dwc3: disable USB core PHY management" (with/without this
>> patch makes no difference)
>> * usb: dwc3: Do not get extcon device when usb-role-switch is used
>> (with/without this patch makes no difference)
>>
>> ftrace shows tusb1210 is indeed still probed, nevertheless in host mode
>> it seems vbus is not powered as my connected smsc95xx based hub is not
>> active (seems not plugged).
>>
>> Flipping the switch to device mode gadgets work fine.
>>
>> Could it be dwc3_host_init() needs to be called prior to otg_set_vbus()?
> 
> Huh, thanks for testing!
> 
> For the platform I'm working on I need to set the phy mode before dwc3_host_init()
> and then found the same code further below in dwc3_core_init_mode,
> 
> static int dwc3_core_init_mode(struct dwc3 *dwc)
> {
> [...]
> 	case USB_DR_MODE_HOST:
> 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
> 
> 		if (dwc->usb2_phy)
> 			otg_set_vbus(dwc->usb2_phy->otg, true);
> 		phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
> 		phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
> 
> 		ret = dwc3_host_init(dwc);
> 		if (ret)
> 			return dev_err_probe(dev, ret, "failed to initialize host\n");
> 		break;
> [...]
> }
> 
> so I'm quite surprised it causes issue in __dwc3_set_mode now.
> If otg_set_vbus indeed needs to happen after dwc3_host_init it should probably
> also be called afterwards in dwc3_core_init_mode as well.

Maybe there is a difference between the case USB_DR_MODE_HOST above and 
case USB_DR_MODE_OTG touched by this patch?
> 
> Best,
> 
> 
> Sven

Re: [PATCH] usb: dwc3: core: configure PHY before initializing host in dwc3_set_mode

[Sven Peter]

On Sun, Nov 13, 2022, at 00:07, Ferry Toth wrote:
> Hi,
>
> Op 12-11-2022 om 23:46 schreef Sven Peter:
>> Hi Ferry,
>> 
>> On Sat, Nov 12, 2022, at 23:15, Ferry Toth wrote:
>>> Hi Sven,
>>>
>>> Op 12-11-2022 om 11:25 schreef Sven Peter:
>>>> Usually, first the PHY is set to the correct mode and then the host or
>>>> device side of the controller is initialized afterwards. Otherwise a PHY
>>>> that's already used has to be reconfigured.
>>>> dwc3_core_init_mode() does this correctly for both host and device and
>>>> __dwc3_set_mode() does it correctly when switching to device mode.
>>>> When setting up host mode however it first initializes xhci and only
>>>> then changes the PHY's mode. Let's also do the operations in the correct
>>>> order here.
>>>>
>>>> Fixes: 958d1a4c40dd ("usb: dwc3: core: program PHY for proper DRD modes")
>>>> Signed-off-by: Sven Peter <sven@svenpeter.dev>
>>>> ---
>>>>    drivers/usb/dwc3/core.c | 9 +++++----
>>>>    1 file changed, 5 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
>>>> index ad4d644e21a4..759d23d908fa 100644
>>>> --- a/drivers/usb/dwc3/core.c
>>>> +++ b/drivers/usb/dwc3/core.c
>>>> @@ -212,14 +212,15 @@ static void __dwc3_set_mode(struct work_struct *work)
>>>>    
>>>>    	switch (dwc->desired_dr_role) {
>>>>    	case DWC3_GCTL_PRTCAP_HOST:
>>>> +		if (dwc->usb2_phy)
>>>> +			otg_set_vbus(dwc->usb2_phy->otg, true);
>>>> +		phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
>>>> +		phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>>>> +
>>>>    		ret = dwc3_host_init(dwc);
>>>>    		if (ret) {
>>>>    			dev_err(dwc->dev, "failed to initialize host\n");
>>>>    		} else {
>>>> -			if (dwc->usb2_phy)
>>>> -				otg_set_vbus(dwc->usb2_phy->otg, true);
>>>> -			phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
>>>> -			phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>>>>    			if (dwc->dis_split_quirk) {
>>>>    				reg = dwc3_readl(dwc->regs, DWC3_GUCTL3);
>>>>    				reg |= DWC3_GUCTL3_SPLITDISABLE;
>>> This patch breaks usb host mode on Intel Merrifield platform. I am
>>> testing this on top of v6.0 +
>>> * my 2 "usb: dwc3: core: defer probe on ulpi_read_id timeout" patches
>>> (otherwise tusb1210 will not be probed on this platform)
>>> * Revert "usb: dwc3: disable USB core PHY management" (with/without this
>>> patch makes no difference)
>>> * usb: dwc3: Do not get extcon device when usb-role-switch is used
>>> (with/without this patch makes no difference)
>>>
>>> ftrace shows tusb1210 is indeed still probed, nevertheless in host mode
>>> it seems vbus is not powered as my connected smsc95xx based hub is not
>>> active (seems not plugged).
>>>
>>> Flipping the switch to device mode gadgets work fine.
>>>
>>> Could it be dwc3_host_init() needs to be called prior to otg_set_vbus()?
>> 
>> Huh, thanks for testing!
>> 
>> For the platform I'm working on I need to set the phy mode before dwc3_host_init()
>> and then found the same code further below in dwc3_core_init_mode,
>> 
>> static int dwc3_core_init_mode(struct dwc3 *dwc)
>> {
>> [...]
>> 	case USB_DR_MODE_HOST:
>> 		dwc3_set_prtcap(dwc, DWC3_GCTL_PRTCAP_HOST);
>> 
>> 		if (dwc->usb2_phy)
>> 			otg_set_vbus(dwc->usb2_phy->otg, true);
>> 		phy_set_mode(dwc->usb2_generic_phy, PHY_MODE_USB_HOST);
>> 		phy_set_mode(dwc->usb3_generic_phy, PHY_MODE_USB_HOST);
>> 
>> 		ret = dwc3_host_init(dwc);
>> 		if (ret)
>> 			return dev_err_probe(dev, ret, "failed to initialize host\n");
>> 		break;
>> [...]
>> }
>> 
>> so I'm quite surprised it causes issue in __dwc3_set_mode now.
>> If otg_set_vbus indeed needs to happen after dwc3_host_init it should probably
>> also be called afterwards in dwc3_core_init_mode as well.
>
> Maybe there is a difference between the case USB_DR_MODE_HOST above and 
> case USB_DR_MODE_OTG touched by this patch?

Would be surprising but who knows. I'll see if I can move more of the PHY
initialization on my platform to the power_on callback so that it'll also
work there with the current code.
I just thought this was going to fix a bug but if it breaks things it's better
to just drop this patch.


Thanks,


Sven