linux-kernel - [PATCH v1 1/1] serial: 8250_port: Drop duplicate NULL check

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Message-ID: <20260128142726.128175-1-andriy.shevchenko@linux.intel.com>
Date: Wed, 28 Jan 2026 15:27:26 +0100
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	"Jiri Slaby (SUSE)" <jirislaby@...nel.org>,
	linux-kernel@...r.kernel.org,
	linux-serial@...r.kernel.org
Cc: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v1 1/1] serial: 8250_port: Drop duplicate NULL check

serial8250_release_dma() is NULL-aware, no need to check this in the caller.
While at it, make sure DMA won't be used again, by NULLifying the pointer.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 drivers/tty/serial/8250/8250_port.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 21fdf84f118f..c40d750d5a4b 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2366,8 +2366,8 @@ void serial8250_do_shutdown(struct uart_port *port)
 
 	synchronize_irq(port->irq);
 
-	if (up->dma)
-		serial8250_release_dma(up);
+	serial8250_release_dma(up);
+	up->dma = NULL;
 
 	scoped_guard(uart_port_lock_irqsave, port) {
 		if (port->flags & UPF_FOURPORT) {
-- 
2.50.1