From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:42068 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752721AbdF0MUQ (ORCPT ); Tue, 27 Jun 2017 08:20:16 -0400 Subject: Patch "dmaengine: bcm2835: Fix cyclic DMA period splitting" has been added to the 4.9-stable tree To: hias@horus.com, amit.pundir@linaro.org, clive.messer@digitaldreamtime.co.uk, eric@anholt.net, gregkh@linuxfoundation.org, kernel@martin.sperl.org, vinod.koul@intel.com Cc: , From: Date: Tue, 27 Jun 2017 14:20:15 +0200 Message-ID: <149856601590164@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled dmaengine: bcm2835: Fix cyclic DMA period splitting to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: dmaengine-bcm2835-fix-cyclic-dma-period-splitting.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 2201ac6129fa162ac24da089a034bb0971648ebb Mon Sep 17 00:00:00 2001 From: Matthias Reichl Date: Mon, 20 Feb 2017 20:01:16 +0100 Subject: dmaengine: bcm2835: Fix cyclic DMA period splitting From: Matthias Reichl commit 2201ac6129fa162ac24da089a034bb0971648ebb upstream. The code responsible for splitting periods into chunks that can be handled by the DMA controller missed to update total_len, the number of bytes processed in the current period, when there are more chunks to follow. Therefore total_len was stuck at 0 and the code didn't work at all. This resulted in a wrong control block layout and audio issues because the cyclic DMA callback wasn't executing on period boundaries. Fix this by adding the missing total_len update. Signed-off-by: Matthias Reichl Signed-off-by: Martin Sperl Tested-by: Clive Messer Reviewed-by: Eric Anholt Signed-off-by: Vinod Koul Signed-off-by: Amit Pundir Signed-off-by: Greg Kroah-Hartman --- drivers/dma/bcm2835-dma.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/dma/bcm2835-dma.c +++ b/drivers/dma/bcm2835-dma.c @@ -251,8 +251,11 @@ static void bcm2835_dma_create_cb_set_le */ /* have we filled in period_length yet? */ - if (*total_len + control_block->length < period_len) + if (*total_len + control_block->length < period_len) { + /* update number of bytes in this period so far */ + *total_len += control_block->length; return; + } /* calculate the length that remains to reach period_length */ control_block->length = period_len - *total_len; Patches currently in stable-queue which might be from hias@horus.com are queue-4.9/dmaengine-bcm2835-fix-cyclic-dma-period-splitting.patch