From mboxrd@z Thu Jan 1 00:00:00 1970 From: tixy@linaro.org (Jon Medhurst) Date: Fri, 7 Nov 2014 18:05:18 +0000 Subject: [PATCH 2/2] dma: pl330: Limit MFIFO usage for memcpy to avoid exhausting entries In-Reply-To: <1415383518-29327-1-git-send-email-tixy@linaro.org> References: <1415383518-29327-1-git-send-email-tixy@linaro.org> Message-ID: <1415383518-29327-3-git-send-email-tixy@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The MFIFO is shared by all channels so restrict each memcpy to it's fair share. This is being over cautious, but without a global view of DMA channel usage on a system it's not possible to come up with a more optimum safe limit. Signed-off-by: Jon Medhurst --- drivers/dma/pl330.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 8f869ec..849439a 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2336,7 +2336,7 @@ static inline int get_burst_len(struct dma_pl330_desc *desc, size_t len) int burst_len; burst_len = pl330->pcfg.data_bus_width / 8; - burst_len *= pl330->pcfg.data_buf_dep; + burst_len *= pl330->pcfg.data_buf_dep / pl330->pcfg.num_chan; burst_len >>= desc->rqcfg.brst_size; /* src/dst_burst_len can't be more than 16 */ -- 2.1.1