linux-kernel - [PATCH 3/4] serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221107110708.58223-4-ilpo.jarvinen@linux.intel.com>
Date:   Mon,  7 Nov 2022 13:07:07 +0200
From:   Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>,
        linux-serial@...r.kernel.org, linux-kernel@...r.kernel.org,
        Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>
Cc:     stable@...r.kernel.org, Wentong Wu <wentong.wu@...el.com>,
        Srikanth Thokala <srikanth.thokala@...el.com>,
        Aman Kumar <aman.kumar@...el.com>
Subject: [PATCH 3/4] serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake

Configure DMA to use 16B burst size with Elkhart Lake. This makes the
bus use more efficient and works around an issue which occurs with the
previously used 1B.

Fixes: 0a9410b981e9 ("serial: 8250_lpss: Enable DMA on Intel Elkhart Lake")
Cc: <stable@...r.kernel.org> # serial: 8250_lpss: Configure DMA also w/o DMA filter
Reported-by: Wentong Wu <wentong.wu@...el.com>
Co-developed-by: Srikanth Thokala <srikanth.thokala@...el.com>
Signed-off-by: Srikanth Thokala <srikanth.thokala@...el.com>
Co-developed-by: Aman Kumar <aman.kumar@...el.com>
Signed-off-by: Aman Kumar <aman.kumar@...el.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>

---
I know the list of Co-dev-bys & Sob seems a bit odd for a oneliner.
The reason is that I cleaned up this from a more complex patch using
the earlier change that I authored myself so only this oneliner
remained in this patch.
---
 drivers/tty/serial/8250/8250_lpss.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_lpss.c b/drivers/tty/serial/8250/8250_lpss.c
index ed281445a97d..e0b4e1446eac 100644
--- a/drivers/tty/serial/8250/8250_lpss.c
+++ b/drivers/tty/serial/8250/8250_lpss.c
@@ -174,6 +174,8 @@ static int ehl_serial_setup(struct lpss8250 *lpss, struct uart_port *port)
 	 */
 	up->dma = dma;
 
+	lpss->dma_maxburst = 16;
+
 	port->set_termios = dw8250_do_set_termios;
 
 	return 0;
-- 
2.30.2