On Wed, Nov 11, 2026 at 08:23:30PM +0200, Aviv Levinson wrote:

Migrate the minor number allocation from the legacy IDR API to the modern XArray API to take advantage of its built-in thread safety.

But why?

As part of this migration, the global `table_lock` mutex has been removed. Mutating operations now rely on XArray's internal spinlocks, and the lookup logic in get_gb_by_minor() has been updated to use rcu_read_lock() combined with kref_get_unless_zero() to safely pin the device reference without blocking.

How was this found and generated and tested?

And kref_get_unless_zero() is almost always a call you never want to make.

Signed-off-by: Aviv Levinson levinson.aviv@gmail.com

drivers/staging/greybus/uart.c | 37 ++++++++++++++++++---------------- 1 file changed, 20 insertions(+), 17 deletions(-)

So now there is more code? That feels like a step backwards, don't you think?

thanks,

greg k-h