From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932255Ab3API5f (ORCPT ); Wed, 16 Jan 2013 03:57:35 -0500 Received: from mga09.intel.com ([134.134.136.24]:62713 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932108Ab3API5e (ORCPT ); Wed, 16 Jan 2013 03:57:34 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.84,478,1355126400"; d="scan'208";a="272670698" From: Andy Shevchenko To: Viresh Kumar , Vinod Koul , linux-kernel@vger.kernel.org, spear-devel Cc: Andy Shevchenko Subject: [PATCHv2] dw_dmac: don't exceed AHB master number in dwc_get_data_width Date: Wed, 16 Jan 2013 10:57:17 +0200 Message-Id: <1358326637-10109-1-git-send-email-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The driver's default assumes that hardware has two AHB masters which might be not true. In such rare cases we have not to exceed a number of the AHB masters present in the hardware. Thus, the AHB master with highest possible number will be used to retrieve the data witdh value. The patch also changes the logic a bit when the master parameter of the dwc_get_data_width() is out of range. Now the function will return a value related to the first AHB master. Signed-off-by: Andy Shevchenko --- drivers/dma/dw_dmac.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index 30ff2a4..561bb9a 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -46,13 +46,29 @@ static inline unsigned int dwc_get_sms(struct dw_dma_slave *slave) return slave ? slave->src_master : 1; } +#define SRC_MASTER 0 +#define DST_MASTER 1 + +static inline unsigned int dwc_get_master(struct dma_chan *chan, int master) +{ + struct dw_dma *dw = to_dw_dma(chan->device); + struct dw_dma_slave *dws = chan->private; + unsigned int m = 0; + + if (master == SRC_MASTER) + m = dwc_get_sms(dws); + else if (master == DST_MASTER) + m = dwc_get_dms(dws); + + return min_t(unsigned int, dw->nr_masters - 1, m); +} + #define DWC_DEFAULT_CTLLO(_chan) ({ \ - struct dw_dma_slave *__slave = (_chan->private); \ struct dw_dma_chan *_dwc = to_dw_dma_chan(_chan); \ struct dma_slave_config *_sconfig = &_dwc->dma_sconfig; \ bool _is_slave = is_slave_direction(_dwc->direction); \ - int _dms = dwc_get_dms(__slave); \ - int _sms = dwc_get_sms(__slave); \ + int _dms = dwc_get_master(_chan, DST_MASTER); \ + int _sms = dwc_get_master(_chan, SRC_MASTER); \ u8 _smsize = _is_slave ? _sconfig->src_maxburst : \ DW_DMA_MSIZE_16; \ u8 _dmsize = _is_slave ? _sconfig->dst_maxburst : \ @@ -73,20 +89,11 @@ static inline unsigned int dwc_get_sms(struct dw_dma_slave *slave) */ #define NR_DESCS_PER_CHANNEL 64 -#define SRC_MASTER 0 -#define DST_MASTER 1 - static inline unsigned int dwc_get_data_width(struct dma_chan *chan, int master) { struct dw_dma *dw = to_dw_dma(chan->device); - struct dw_dma_slave *dws = chan->private; - if (master == SRC_MASTER) - return dw->data_width[dwc_get_sms(dws)]; - else if (master == DST_MASTER) - return dw->data_width[dwc_get_dms(dws)]; - - return 0; + return dw->data_width[dwc_get_master(chan, master)]; } /*----------------------------------------------------------------------*/ -- 1.7.10.4