[v6,09/10] usb: dwc3: qcom: Detect DWC3 DT-nodes with "usb"-prefixed names

Commit Message

Serge Semin Feb. 10, 2021, 5:28 p.m. UTC

In accordance with the USB HCD/DRD schema all the USB controllers are
supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
existing DT-nodes will be renamed in a subsequent patch let's first make
sure the DWC3 Qualcomm driver supports them and second falls back to the
deprecated naming so not to fail on the legacy DTS-files passed to the
newer kernels.

Signed-off-by: Serge Semin <[e-mail]>
Reviewed-by: Bjorn Andersson <[e-mail]>
---
 drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Rob Herring Feb. 10, 2021, 6:17 p.m. UTC | #1

On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
<[e-mail]> wrote:
>
> In accordance with the USB HCD/DRD schema all the USB controllers are
> supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> existing DT-nodes will be renamed in a subsequent patch let's first make
> sure the DWC3 Qualcomm driver supports them and second falls back to the
> deprecated naming so not to fail on the legacy DTS-files passed to the
> newer kernels.
>
> Signed-off-by: Serge Semin <[e-mail]>
> Reviewed-by: Bjorn Andersson <[e-mail]>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index c703d552bbcf..49ad8d507d37 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
>         struct device           *dev = &pdev->dev;
>         int                     ret;
>
> -       dwc3_np = of_get_child_by_name(np, "dwc3");
> +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> +                 of_get_child_by_name(np, "dwc3");

Is there some reason using compatible instead wouldn't work here?

Rob

Serge Semin Feb. 10, 2021, 6:40 p.m. UTC | #2

On Wed, Feb 10, 2021 at 12:17:27PM -0600, Rob Herring wrote:
> On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
> <[e-mail]> wrote:
> >
> > In accordance with the USB HCD/DRD schema all the USB controllers are
> > supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> > existing DT-nodes will be renamed in a subsequent patch let's first make
> > sure the DWC3 Qualcomm driver supports them and second falls back to the
> > deprecated naming so not to fail on the legacy DTS-files passed to the
> > newer kernels.
> >
> > Signed-off-by: Serge Semin <[e-mail]>
> > Reviewed-by: Bjorn Andersson <[e-mail]>
> > ---
> >  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > index c703d552bbcf..49ad8d507d37 100644
> > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> >         struct device           *dev = &pdev->dev;
> >         int                     ret;
> >
> > -       dwc3_np = of_get_child_by_name(np, "dwc3");
> > +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> > +                 of_get_child_by_name(np, "dwc3");
> 

> Is there some reason using compatible instead wouldn't work here?

I don't know for sure. The fix has been requested in the framework of
this discussion:
https://lore.kernel.org/linux-usb/[e-mail]/#t
by the driver maintainer Bjorn. To get a firm answer it's better to
have him asked. As I see it having of_get_compatible_child() utilized
here would also work. At least for the available in kernel dt-files.
See the affected dts-es in:
https://lore.kernel.org/linux-usb/[e-mail]/

A problem may happen if some older versions of DTS-es had another
compatible string in the dwc3 sub-node...

-Sergey

> 
> Rob

Bjorn Andersson Feb. 10, 2021, 6:56 p.m. UTC | #3

On Wed 10 Feb 12:40 CST 2021, Serge Semin wrote:

> On Wed, Feb 10, 2021 at 12:17:27PM -0600, Rob Herring wrote:
> > On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
> > <[e-mail]> wrote:
> > >
> > > In accordance with the USB HCD/DRD schema all the USB controllers are
> > > supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> > > existing DT-nodes will be renamed in a subsequent patch let's first make
> > > sure the DWC3 Qualcomm driver supports them and second falls back to the
> > > deprecated naming so not to fail on the legacy DTS-files passed to the
> > > newer kernels.
> > >
> > > Signed-off-by: Serge Semin <[e-mail]>
> > > Reviewed-by: Bjorn Andersson <[e-mail]>
> > > ---
> > >  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > > index c703d552bbcf..49ad8d507d37 100644
> > > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > > @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> > >         struct device           *dev = &pdev->dev;
> > >         int                     ret;
> > >
> > > -       dwc3_np = of_get_child_by_name(np, "dwc3");
> > > +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> > > +                 of_get_child_by_name(np, "dwc3");
> > 
> 
> > Is there some reason using compatible instead wouldn't work here?
> 
> I don't know for sure. The fix has been requested in the framework of
> this discussion:
> https://lore.kernel.org/linux-usb/[e-mail]/#t
> by the driver maintainer Bjorn. To get a firm answer it's better to
> have him asked.

My feedback was simply that it has to catch both cases, I didn't
consider the fact that we have a compatible to match against.

> As I see it having of_get_compatible_child() utilized
> here would also work. At least for the available in kernel dt-files.
> See the affected dts-es in:
> https://lore.kernel.org/linux-usb/[e-mail]/
> 
> A problem may happen if some older versions of DTS-es had another
> compatible string in the dwc3 sub-node...
> 

Afaict all Qualcomm dts files has "snps,dwc3", so you can match against
that instead.

Regards,
Bjorn

Rob Herring Feb. 10, 2021, 6:59 p.m. UTC | #4

On Wed, Feb 10, 2021 at 12:40 PM Serge Semin
<[e-mail]> wrote:
>
> On Wed, Feb 10, 2021 at 12:17:27PM -0600, Rob Herring wrote:
> > On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
> > <[e-mail]> wrote:
> > >
> > > In accordance with the USB HCD/DRD schema all the USB controllers are
> > > supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> > > existing DT-nodes will be renamed in a subsequent patch let's first make
> > > sure the DWC3 Qualcomm driver supports them and second falls back to the
> > > deprecated naming so not to fail on the legacy DTS-files passed to the
> > > newer kernels.
> > >
> > > Signed-off-by: Serge Semin <[e-mail]>
> > > Reviewed-by: Bjorn Andersson <[e-mail]>
> > > ---
> > >  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > > index c703d552bbcf..49ad8d507d37 100644
> > > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > > @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> > >         struct device           *dev = &pdev->dev;
> > >         int                     ret;
> > >
> > > -       dwc3_np = of_get_child_by_name(np, "dwc3");
> > > +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> > > +                 of_get_child_by_name(np, "dwc3");
> >
>
> > Is there some reason using compatible instead wouldn't work here?
>
> I don't know for sure. The fix has been requested in the framework of
> this discussion:
> https://lore.kernel.org/linux-usb/[e-mail]/#t
> by the driver maintainer Bjorn. To get a firm answer it's better to
> have him asked. As I see it having of_get_compatible_child() utilized
> here would also work. At least for the available in kernel dt-files.
> See the affected dts-es in:
> https://lore.kernel.org/linux-usb/[e-mail]/
>
> A problem may happen if some older versions of DTS-es had another
> compatible string in the dwc3 sub-node...

I guess there's some 'synopsys,dwc3' too, but looking at 2 compatibles
is better than looking at 2 node names. We try to not care what node
names are generally.

Rob

Serge Semin Feb. 10, 2021, 7:33 p.m. UTC | #5

On Wed, Feb 10, 2021 at 12:56:59PM -0600, Bjorn Andersson wrote:
> On Wed 10 Feb 12:40 CST 2021, Serge Semin wrote:
> 
> > On Wed, Feb 10, 2021 at 12:17:27PM -0600, Rob Herring wrote:
> > > On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
> > > <[e-mail]> wrote:
> > > >
> > > > In accordance with the USB HCD/DRD schema all the USB controllers are
> > > > supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> > > > existing DT-nodes will be renamed in a subsequent patch let's first make
> > > > sure the DWC3 Qualcomm driver supports them and second falls back to the
> > > > deprecated naming so not to fail on the legacy DTS-files passed to the
> > > > newer kernels.
> > > >
> > > > Signed-off-by: Serge Semin <[e-mail]>
> > > > Reviewed-by: Bjorn Andersson <[e-mail]>
> > > > ---
> > > >  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
> > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > > > index c703d552bbcf..49ad8d507d37 100644
> > > > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > > > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > > > @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> > > >         struct device           *dev = &pdev->dev;
> > > >         int                     ret;
> > > >
> > > > -       dwc3_np = of_get_child_by_name(np, "dwc3");
> > > > +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> > > > +                 of_get_child_by_name(np, "dwc3");
> > > 
> > 
> > > Is there some reason using compatible instead wouldn't work here?
> > 
> > I don't know for sure. The fix has been requested in the framework of
> > this discussion:
> > https://lore.kernel.org/linux-usb/[e-mail]/#t
> > by the driver maintainer Bjorn. To get a firm answer it's better to
> > have him asked.
> 
> My feedback was simply that it has to catch both cases, I didn't
> consider the fact that we have a compatible to match against.
> 
> > As I see it having of_get_compatible_child() utilized
> > here would also work. At least for the available in kernel dt-files.
> > See the affected dts-es in:
> > https://lore.kernel.org/linux-usb/[e-mail]/
> > 
> > A problem may happen if some older versions of DTS-es had another
> > compatible string in the dwc3 sub-node...
> > 
> 
> Afaict all Qualcomm dts files has "snps,dwc3", so you can match against
> that instead.

Ok then. I'll replace of_get_child_by_name() here with
of_get_compatible_child() matching just against "snps,dwc3" in v7. Can you
confirm that noone ever had a Qcom-based hardware described with dts having
the "synopsys,dwc3" compatible used as the DWC USB3 sub-node here? That
string has been marked as deprecated recently because the vendor-prefix
was changed sometime ago, but the original driver still accept it.

Alternatively to be on a safe side we could match against both
compatibles here as Rob suggests. What do you think?

-Sergey

> 
> Regards,
> Bjorn

Serge Semin Feb. 12, 2021, 5:33 p.m. UTC | #6

On Wed, Feb 10, 2021 at 10:33:26PM +0300, Serge Semin wrote:
> On Wed, Feb 10, 2021 at 12:56:59PM -0600, Bjorn Andersson wrote:
> > On Wed 10 Feb 12:40 CST 2021, Serge Semin wrote:
> > 
> > > On Wed, Feb 10, 2021 at 12:17:27PM -0600, Rob Herring wrote:
> > > > On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
> > > > <[e-mail]> wrote:
> > > > >
> > > > > In accordance with the USB HCD/DRD schema all the USB controllers are
> > > > > supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> > > > > existing DT-nodes will be renamed in a subsequent patch let's first make
> > > > > sure the DWC3 Qualcomm driver supports them and second falls back to the
> > > > > deprecated naming so not to fail on the legacy DTS-files passed to the
> > > > > newer kernels.
> > > > >
> > > > > Signed-off-by: Serge Semin <[e-mail]>
> > > > > Reviewed-by: Bjorn Andersson <[e-mail]>
> > > > > ---
> > > > >  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
> > > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > index c703d552bbcf..49ad8d507d37 100644
> > > > > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > > > > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> > > > >         struct device           *dev = &pdev->dev;
> > > > >         int                     ret;
> > > > >
> > > > > -       dwc3_np = of_get_child_by_name(np, "dwc3");
> > > > > +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> > > > > +                 of_get_child_by_name(np, "dwc3");
> > > > 
> > > 
> > > > Is there some reason using compatible instead wouldn't work here?
> > > 
> > > I don't know for sure. The fix has been requested in the framework of
> > > this discussion:
> > > https://lore.kernel.org/linux-usb/[e-mail]/#t
> > > by the driver maintainer Bjorn. To get a firm answer it's better to
> > > have him asked.
> > 
> > My feedback was simply that it has to catch both cases, I didn't
> > consider the fact that we have a compatible to match against.
> > 
> > > As I see it having of_get_compatible_child() utilized
> > > here would also work. At least for the available in kernel dt-files.
> > > See the affected dts-es in:
> > > https://lore.kernel.org/linux-usb/[e-mail]/
> > > 
> > > A problem may happen if some older versions of DTS-es had another
> > > compatible string in the dwc3 sub-node...
> > > 
> > 
> > Afaict all Qualcomm dts files has "snps,dwc3", so you can match against
> > that instead.
> 
> Ok then. I'll replace of_get_child_by_name() here with
> of_get_compatible_child() matching just against "snps,dwc3" in v7. Can you
> confirm that noone ever had a Qcom-based hardware described with dts having
> the "synopsys,dwc3" compatible used as the DWC USB3 sub-node here? That
> string has been marked as deprecated recently because the vendor-prefix
> was changed sometime ago, but the original driver still accept it.
> 
> Alternatively to be on a safe side we could match against both
> compatibles here as Rob suggests. What do you think?

Bjorn, any comment on the question above? So I could respin the series
with this patch updated.

Also note, since the patch's gonna be changed I'll have to remove your
Reviewed-by tag unless u explicitly say I shouldn't.

-Sergey

> 
> -Sergey
> 
> > 
> > Regards,
> > Bjorn

Bjorn Andersson Feb. 12, 2021, 5:49 p.m. UTC | #7

On Wed 10 Feb 13:33 CST 2021, Serge Semin wrote:

> On Wed, Feb 10, 2021 at 12:56:59PM -0600, Bjorn Andersson wrote:
> > On Wed 10 Feb 12:40 CST 2021, Serge Semin wrote:
> > 
> > > On Wed, Feb 10, 2021 at 12:17:27PM -0600, Rob Herring wrote:
> > > > On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
> > > > <[e-mail]> wrote:
> > > > >
> > > > > In accordance with the USB HCD/DRD schema all the USB controllers are
> > > > > supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> > > > > existing DT-nodes will be renamed in a subsequent patch let's first make
> > > > > sure the DWC3 Qualcomm driver supports them and second falls back to the
> > > > > deprecated naming so not to fail on the legacy DTS-files passed to the
> > > > > newer kernels.
> > > > >
> > > > > Signed-off-by: Serge Semin <[e-mail]>
> > > > > Reviewed-by: Bjorn Andersson <[e-mail]>
> > > > > ---
> > > > >  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
> > > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > > >
> > > > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > index c703d552bbcf..49ad8d507d37 100644
> > > > > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > > > > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> > > > >         struct device           *dev = &pdev->dev;
> > > > >         int                     ret;
> > > > >
> > > > > -       dwc3_np = of_get_child_by_name(np, "dwc3");
> > > > > +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> > > > > +                 of_get_child_by_name(np, "dwc3");
> > > > 
> > > 
> > > > Is there some reason using compatible instead wouldn't work here?
> > > 
> > > I don't know for sure. The fix has been requested in the framework of
> > > this discussion:
> > > https://lore.kernel.org/linux-usb/[e-mail]/#t
> > > by the driver maintainer Bjorn. To get a firm answer it's better to
> > > have him asked.
> > 
> > My feedback was simply that it has to catch both cases, I didn't
> > consider the fact that we have a compatible to match against.
> > 
> > > As I see it having of_get_compatible_child() utilized
> > > here would also work. At least for the available in kernel dt-files.
> > > See the affected dts-es in:
> > > https://lore.kernel.org/linux-usb/[e-mail]/
> > > 
> > > A problem may happen if some older versions of DTS-es had another
> > > compatible string in the dwc3 sub-node...
> > > 
> > 
> > Afaict all Qualcomm dts files has "snps,dwc3", so you can match against
> > that instead.
> 
> Ok then. I'll replace of_get_child_by_name() here with
> of_get_compatible_child() matching just against "snps,dwc3" in v7. Can you
> confirm that noone ever had a Qcom-based hardware described with dts having
> the "synopsys,dwc3" compatible used as the DWC USB3 sub-node here? That
> string has been marked as deprecated recently because the vendor-prefix
> was changed sometime ago, but the original driver still accept it.
> 

I don't see any Qualcomm users of "synopsys,dwc3", past or present.

> Alternatively to be on a safe side we could match against both
> compatibles here as Rob suggests. What do you think?
> 

Let's go with only "snps,dwc3".

Regards,
Bjorn

Bjorn Andersson Feb. 12, 2021, 6:01 p.m. UTC | #8

On Fri 12 Feb 11:33 CST 2021, Serge Semin wrote:

> On Wed, Feb 10, 2021 at 10:33:26PM +0300, Serge Semin wrote:
> > On Wed, Feb 10, 2021 at 12:56:59PM -0600, Bjorn Andersson wrote:
> > > On Wed 10 Feb 12:40 CST 2021, Serge Semin wrote:
> > > 
> > > > On Wed, Feb 10, 2021 at 12:17:27PM -0600, Rob Herring wrote:
> > > > > On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
> > > > > <[e-mail]> wrote:
> > > > > >
> > > > > > In accordance with the USB HCD/DRD schema all the USB controllers are
> > > > > > supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> > > > > > existing DT-nodes will be renamed in a subsequent patch let's first make
> > > > > > sure the DWC3 Qualcomm driver supports them and second falls back to the
> > > > > > deprecated naming so not to fail on the legacy DTS-files passed to the
> > > > > > newer kernels.
> > > > > >
> > > > > > Signed-off-by: Serge Semin <[e-mail]>
> > > > > > Reviewed-by: Bjorn Andersson <[e-mail]>
> > > > > > ---
> > > > > >  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
> > > > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > > > >
> > > > > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > index c703d552bbcf..49ad8d507d37 100644
> > > > > > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> > > > > >         struct device           *dev = &pdev->dev;
> > > > > >         int                     ret;
> > > > > >
> > > > > > -       dwc3_np = of_get_child_by_name(np, "dwc3");
> > > > > > +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> > > > > > +                 of_get_child_by_name(np, "dwc3");
> > > > > 
> > > > 
> > > > > Is there some reason using compatible instead wouldn't work here?
> > > > 
> > > > I don't know for sure. The fix has been requested in the framework of
> > > > this discussion:
> > > > https://lore.kernel.org/linux-usb/[e-mail]/#t
> > > > by the driver maintainer Bjorn. To get a firm answer it's better to
> > > > have him asked.
> > > 
> > > My feedback was simply that it has to catch both cases, I didn't
> > > consider the fact that we have a compatible to match against.
> > > 
> > > > As I see it having of_get_compatible_child() utilized
> > > > here would also work. At least for the available in kernel dt-files.
> > > > See the affected dts-es in:
> > > > https://lore.kernel.org/linux-usb/[e-mail]/
> > > > 
> > > > A problem may happen if some older versions of DTS-es had another
> > > > compatible string in the dwc3 sub-node...
> > > > 
> > > 
> > > Afaict all Qualcomm dts files has "snps,dwc3", so you can match against
> > > that instead.
> > 
> > Ok then. I'll replace of_get_child_by_name() here with
> > of_get_compatible_child() matching just against "snps,dwc3" in v7. Can you
> > confirm that noone ever had a Qcom-based hardware described with dts having
> > the "synopsys,dwc3" compatible used as the DWC USB3 sub-node here? That
> > string has been marked as deprecated recently because the vendor-prefix
> > was changed sometime ago, but the original driver still accept it.
> > 
> > Alternatively to be on a safe side we could match against both
> > compatibles here as Rob suggests. What do you think?
> 
> Bjorn, any comment on the question above? So I could respin the series
> with this patch updated.
> 
> Also note, since the patch's gonna be changed I'll have to remove your
> Reviewed-by tag unless u explicitly say I shouldn't.
> 

Sounds good, I'd be happy to review the new patch.

PS. As this only affect the Qualcomm part of the series I would suggest
that you send these patches off separate and don't send all 10 patches
together.

Thanks,
Bjorn

Serge Semin Feb. 12, 2021, 7:51 p.m. UTC | #9

On Fri, Feb 12, 2021 at 11:49:15AM -0600, Bjorn Andersson wrote:
> On Wed 10 Feb 13:33 CST 2021, Serge Semin wrote:
> 
> > On Wed, Feb 10, 2021 at 12:56:59PM -0600, Bjorn Andersson wrote:
> > > On Wed 10 Feb 12:40 CST 2021, Serge Semin wrote:
> > > 
> > > > On Wed, Feb 10, 2021 at 12:17:27PM -0600, Rob Herring wrote:
> > > > > On Wed, Feb 10, 2021 at 11:29 AM Serge Semin
> > > > > <[e-mail]> wrote:
> > > > > >
> > > > > > In accordance with the USB HCD/DRD schema all the USB controllers are
> > > > > > supposed to have DT-nodes named with prefix "^usb(@.*)?".  Since the
> > > > > > existing DT-nodes will be renamed in a subsequent patch let's first make
> > > > > > sure the DWC3 Qualcomm driver supports them and second falls back to the
> > > > > > deprecated naming so not to fail on the legacy DTS-files passed to the
> > > > > > newer kernels.
> > > > > >
> > > > > > Signed-off-by: Serge Semin <[e-mail]>
> > > > > > Reviewed-by: Bjorn Andersson <[e-mail]>
> > > > > > ---
> > > > > >  drivers/usb/dwc3/dwc3-qcom.c | 3 ++-
> > > > > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > > > >
> > > > > > diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > index c703d552bbcf..49ad8d507d37 100644
> > > > > > --- a/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > +++ b/drivers/usb/dwc3/dwc3-qcom.c
> > > > > > @@ -630,7 +630,8 @@ static int dwc3_qcom_of_register_core(struct platform_device *pdev)
> > > > > >         struct device           *dev = &pdev->dev;
> > > > > >         int                     ret;
> > > > > >
> > > > > > -       dwc3_np = of_get_child_by_name(np, "dwc3");
> > > > > > +       dwc3_np = of_get_child_by_name(np, "usb") ?:
> > > > > > +                 of_get_child_by_name(np, "dwc3");
> > > > > 
> > > > 
> > > > > Is there some reason using compatible instead wouldn't work here?
> > > > 
> > > > I don't know for sure. The fix has been requested in the framework of
> > > > this discussion:
> > > > https://lore.kernel.org/linux-usb/[e-mail]/#t
> > > > by the driver maintainer Bjorn. To get a firm answer it's better to
> > > > have him asked.
> > > 
> > > My feedback was simply that it has to catch both cases, I didn't
> > > consider the fact that we have a compatible to match against.
> > > 
> > > > As I see it having of_get_compatible_child() utilized
> > > > here would also work. At least for the available in kernel dt-files.
> > > > See the affected dts-es in:
> > > > https://lore.kernel.org/linux-usb/[e-mail]/
> > > > 
> > > > A problem may happen if some older versions of DTS-es had another
> > > > compatible string in the dwc3 sub-node...
> > > > 
> > > 
> > > Afaict all Qualcomm dts files has "snps,dwc3", so you can match against
> > > that instead.
> > 
> > Ok then. I'll replace of_get_child_by_name() here with
> > of_get_compatible_child() matching just against "snps,dwc3" in v7. Can you
> > confirm that noone ever had a Qcom-based hardware described with dts having
> > the "synopsys,dwc3" compatible used as the DWC USB3 sub-node here? That
> > string has been marked as deprecated recently because the vendor-prefix
> > was changed sometime ago, but the original driver still accept it.
> > 
> 
> I don't see any Qualcomm users of "synopsys,dwc3", past or present.
> 
> > Alternatively to be on a safe side we could match against both
> > compatibles here as Rob suggests. What do you think?
> > 
> 
> Let's go with only "snps,dwc3".

Ok. Thanks. I'll resend just two patches in ten minutes.

-Sergey

> 
> Regards,
> Bjorn

Patch

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index c703d552bbcf..49ad8d507d37 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -630,7 +630,8 @@  static int dwc3_qcom_of_register_core(struct platform_device *pdev)
 	struct device		*dev = &pdev->dev;
 	int			ret;
 
-	dwc3_np = of_get_child_by_name(np, "dwc3");
+	dwc3_np = of_get_child_by_name(np, "usb") ?:
+		  of_get_child_by_name(np, "dwc3");
 	if (!dwc3_np) {
 		dev_err(dev, "failed to find dwc3 core child\n");
 		return -ENODEV;