From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3FC221C29 for ; Wed, 23 Nov 2022 09:37:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3A74C433C1; Wed, 23 Nov 2022 09:37:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669196250; bh=Wm780JdXSbVE3bl+bwJfSmQibLKJzF9tiW4tKpyR8Ok=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C8z2VA36JRWju1eI3sQgJudHTSGSOgFrPdMX7OVROEQ27HgPcUnHEj3iDPVsfeJT5 2O5SCL/DUKmEIEpzw71dbbTwI7gy1H4Bq+MfRrLLcCdDTgNVnAg3NrIekNOxxfRaMh Eb4VbGxdwaPF7i27DjQBR1JmZeUchZzm3Pd3Z8q8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Wentong Wu , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , Andy Shevchenko Subject: [PATCH 5.15 159/181] serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake Date: Wed, 23 Nov 2022 09:52:02 +0100 Message-Id: <20221123084609.219780620@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084602.707860461@linuxfoundation.org> References: <20221123084602.707860461@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ilpo Järvinen commit 7090abd6ad0610a144523ce4ffcb8560909bf2a8 upstream. 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. The fix was initially developed by Srikanth Thokala and Aman Kumar. This together with the previous config change is the cleaned up version of the original fix. Fixes: 0a9410b981e9 ("serial: 8250_lpss: Enable DMA on Intel Elkhart Lake") Cc: # serial: 8250_lpss: Configure DMA also w/o DMA filter Reported-by: Wentong Wu Signed-off-by: Ilpo Järvinen Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20221108121952.5497-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_lpss.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/tty/serial/8250/8250_lpss.c +++ b/drivers/tty/serial/8250/8250_lpss.c @@ -177,6 +177,9 @@ static int ehl_serial_setup(struct lpss8 * matching with the registered General Purpose DMA controllers. */ up->dma = dma; + + lpss->dma_maxburst = 16; + return 0; }