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:

quoted

On Mon, Jul 10, 2023 at 06:49:22PM +0300, Andy Shevchenko wrote:

quoted

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