Re: [PATCH] net: qualcomm: qca_uart: report the consumed byte on RX skb allocation failure

[Simon Horman]

On Thu, Apr 02, 2026 at 03:12:07PM +0800, Pengpeng Hou wrote:
> qca_tty_receive() consumes each input byte before checking whether a
> completed frame needs a fresh receive skb. When the current byte completes
> a frame, the driver delivers that frame and then allocates a new skb for
> the next one.
> 
> If that allocation fails, the current code returns i even though data[i]
> has already been consumed and may already have completed the delivered
> frame. Since serdev interprets the return value as the number of accepted
> bytes, this under-reports progress by one byte and can replay the final
> byte of the completed frame into a fresh parser state on the next call.
> 
> Return i + 1 in that failure path so the accepted-byte count matches the
> actual receive-state progress.
> 
> Fixes: dfc768fbe618 ("net: qualcomm: add QCA7000 UART driver")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>

Reviewed-by: Simon Horman <horms@xxxxxxxxxx>