Seems by unknown reason, probably some kind of mis-rebase,
the commit 0c79378c0199 ("spi: add ancillary device support")
adds a dozen of duplicating lines of code. Drop them.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/spi/spi.c | 11 -----------
 1 file changed, 11 deletions(-)

diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index c99ee4164f11..46cbda383228 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -712,17 +712,6 @@ EXPORT_SYMBOL_GPL(spi_add_device);
 static int spi_add_device_locked(struct spi_device *spi)
 {
 	struct spi_controller *ctlr = spi->controller;
-	struct device *dev = ctlr->dev.parent;
-
-	/* Chipselects are numbered 0..max; validate. */
-	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
-		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
-			ctlr->num_chipselect);
-		return -EINVAL;
-	}
-
-	/* Set the bus ID string */
-	spi_dev_set_name(spi);
 
 	WARN_ON(!mutex_is_locked(&ctlr->add_lock));
 	return __spi_add_device(spi);
-- 
2.40.0.1.gaa8946217a0b

On Mon, Jul 10, 2023 at 06:49:22PM +0300, Andy Shevchenko wrote:
> Seems by unknown reason, probably some kind of mis-rebase,
> the commit 0c79378c0199 ("spi: add ancillary device support")
> adds a dozen of duplicating lines of code. Drop them.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/spi/spi.c | 11 -----------
>  1 file changed, 11 deletions(-)
> 
> diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> index c99ee4164f11..46cbda383228 100644
> --- a/drivers/spi/spi.c
> +++ b/drivers/spi/spi.c
> @@ -712,17 +712,6 @@ EXPORT_SYMBOL_GPL(spi_add_device);
>  static int spi_add_device_locked(struct spi_device *spi)
>  {
>  	struct spi_controller *ctlr = spi->controller;
> -	struct device *dev = ctlr->dev.parent;
> -
> -	/* Chipselects are numbered 0..max; validate. */
> -	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> -		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
> -			ctlr->num_chipselect);
> -		return -EINVAL;
> -	}
> -
> -	/* Set the bus ID string */
> -	spi_dev_set_name(spi);

I see that this is duplicating spi_add_device() (and we really could do
better with code sharing there I think) but I can't immediately see
where the duplication that's intended to be elimiated is here - where
else in the one call path that spi_add_device_locked() has would we do
the above?  Based on the changelog I was expecting to see some
duplicated code in the function itself.

On Mon, Jul 10, 2023 at 06:16:22PM +0100, Mark Brown wrote:
> On Mon, Jul 10, 2023 at 06:49:22PM +0300, Andy Shevchenko wrote:
> > Seems by unknown reason, probably some kind of mis-rebase,
> > the commit 0c79378c0199 ("spi: add ancillary device support")
> > adds a dozen of duplicating lines of code. Drop them.
> > 
> > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > ---
> >  drivers/spi/spi.c | 11 -----------
> >  1 file changed, 11 deletions(-)
> > 
> > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> > index c99ee4164f11..46cbda383228 100644
> > --- a/drivers/spi/spi.c
> > +++ b/drivers/spi/spi.c
> > @@ -712,17 +712,6 @@ EXPORT_SYMBOL_GPL(spi_add_device);
> >  static int spi_add_device_locked(struct spi_device *spi)
> >  {
> >  	struct spi_controller *ctlr = spi->controller;
> > -	struct device *dev = ctlr->dev.parent;
> > -
> > -	/* Chipselects are numbered 0..max; validate. */
> > -	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> > -		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
> > -			ctlr->num_chipselect);
> > -		return -EINVAL;
> > -	}
> > -
> > -	/* Set the bus ID string */
> > -	spi_dev_set_name(spi);
> 
> I see that this is duplicating spi_add_device() (and we really could do
> better with code sharing there I think) but I can't immediately see
> where the duplication that's intended to be elimiated is here - where
> else in the one call path that spi_add_device_locked() has would we do
> the above?  Based on the changelog I was expecting to see some
> duplicated code in the function itself.

Oh, by some reason Sebastian wasn't in this rather long Cc list.
Added him.

Reading again I don't see any useful explanation why that piece of code has to
be duplicated among these two functions. It's 100% a copy.

Sebastian, can you shed some light here?

-- 
With Best Regards,
Andy Shevchenko

Hi,

On Tue, Jul 11, 2023 at 02:06:20PM +0300, Andy Shevchenko wrote:
> On Mon, Jul 10, 2023 at 06:16:22PM +0100, Mark Brown wrote:
> > On Mon, Jul 10, 2023 at 06:49:22PM +0300, Andy Shevchenko wrote:
> > > Seems by unknown reason, probably some kind of mis-rebase,
> > > the commit 0c79378c0199 ("spi: add ancillary device support")
> > > adds a dozen of duplicating lines of code. Drop them.
> > > 
> > > Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > > ---
> > >  drivers/spi/spi.c | 11 -----------
> > >  1 file changed, 11 deletions(-)
> > > 
> > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
> > > index c99ee4164f11..46cbda383228 100644
> > > --- a/drivers/spi/spi.c
> > > +++ b/drivers/spi/spi.c
> > > @@ -712,17 +712,6 @@ EXPORT_SYMBOL_GPL(spi_add_device);
> > >  static int spi_add_device_locked(struct spi_device *spi)
> > >  {
> > >  	struct spi_controller *ctlr = spi->controller;
> > > -	struct device *dev = ctlr->dev.parent;
> > > -
> > > -	/* Chipselects are numbered 0..max; validate. */
> > > -	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> > > -		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
> > > -			ctlr->num_chipselect);
> > > -		return -EINVAL;
> > > -	}
> > > -
> > > -	/* Set the bus ID string */
> > > -	spi_dev_set_name(spi);
> > 
> > I see that this is duplicating spi_add_device() (and we really could do
> > better with code sharing there I think) but I can't immediately see
> > where the duplication that's intended to be elimiated is here - where
> > else in the one call path that spi_add_device_locked() has would we do
> > the above?  Based on the changelog I was expecting to see some
> > duplicated code in the function itself.
> 
> Oh, by some reason Sebastian wasn't in this rather long Cc list.
> Added him.
> 
> Reading again I don't see any useful explanation why that piece of code has to
> be duplicated among these two functions. It's 100% a copy.
> 
> Sebastian, can you shed some light here?

The patch in this thread is obviously wrong. It results in the
checks never beeing called for spi_add_device_locked(). The copy is
in spi_add_device() and those two are not calling into each other.

But it should be fine to move the code to the start of
__spi_add_device(), which allows removing the duplication. In that
case the code will be run with the add_lock held, which is probably
what I was worried about two years ago. Looking at it again, the
lock is held anyways in case of spi_add_device_locked().

Greetings,

-- Sebastian

On Tue, Jul 11, 2023 at 02:01:33PM +0200, Sebastian Reichel wrote:
> On Tue, Jul 11, 2023 at 02:06:20PM +0300, Andy Shevchenko wrote:
> > On Mon, Jul 10, 2023 at 06:16:22PM +0100, Mark Brown wrote:
> > > On Mon, Jul 10, 2023 at 06:49:22PM +0300, Andy Shevchenko wrote:

...

> > > > -	struct device *dev = ctlr->dev.parent;
> > > > -
> > > > -	/* Chipselects are numbered 0..max; validate. */
> > > > -	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
> > > > -		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
> > > > -			ctlr->num_chipselect);
> > > > -		return -EINVAL;
> > > > -	}
> > > > -
> > > > -	/* Set the bus ID string */
> > > > -	spi_dev_set_name(spi);
> > > 
> > > I see that this is duplicating spi_add_device() (and we really could do
> > > better with code sharing there I think) but I can't immediately see
> > > where the duplication that's intended to be elimiated is here - where
> > > else in the one call path that spi_add_device_locked() has would we do
> > > the above?  Based on the changelog I was expecting to see some
> > > duplicated code in the function itself.
> > 
> > Oh, by some reason Sebastian wasn't in this rather long Cc list.
> > Added him.
> > 
> > Reading again I don't see any useful explanation why that piece of code has to
> > be duplicated among these two functions. It's 100% a copy.
> > 
> > Sebastian, can you shed some light here?
> 
> The patch in this thread is obviously wrong. It results in the
> checks never beeing called for spi_add_device_locked(). The copy is
> in spi_add_device() and those two are not calling into each other.

Ah, now I see, I missed __ in the name.
Thank you for opening my eyes!

> But it should be fine to move the code to the start of
> __spi_add_device(), which allows removing the duplication. In that
> case the code will be run with the add_lock held, which is probably
> what I was worried about two years ago. Looking at it again, the
> lock is held anyways in case of spi_add_device_locked().

Right, I will re-do that.

-- 
With Best Regards,
Andy Shevchenko