From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Lin Subject: [PATCH v6 08/10] spi: rockchip: modify DMA max burst to 1 Date: Thu, 15 Oct 2015 09:36:26 +0800 Message-ID: <1444872986-2507-1-git-send-email-shawn.lin@rock-chips.com> References: <1444872865-2169-1-git-send-email-shawn.lin@rock-chips.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Addy Ke , Lars-Peter Clausen , alsa-devel-K7yf7f+aM1XWsZ/bQMPhNw@public.gmane.org, Boojin Kim , Shawn Lin , Doug Anderson , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Olof Johansson , linux-rockchip-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sonny Rao , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org To: Vinod Koul , Heiko Stuebner , Jaroslav Kysela , Takashi Iwai , Mark Brown Return-path: In-Reply-To: <1444872865-2169-1-git-send-email-shawn.lin-TNX95d0MmH7DzftRWevZcw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+glpar-linux-rockchip=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-spi.vger.kernel.org From: Addy Ke Generic dma controller on Rockchips' platform cannot support DMAFLUSHP instruction which make dma to flush the req of non-aligned or non-multiple of what we need. That will cause an unrecoverable dma bus error. The saftest way is to set dma max burst to 1. Signed-off-by: Addy ke Fixes: 64e36824b32b06 ("spi/rockchip: add driver for Rockchip...") Signed-off-by: Shawn Lin cc: Heiko Stuebner cc: Olof Johansson cc: Doug Anderson cc: Sonny Rao Acked-by: Mark Brown --- Changes in v6: - remove quirks and get dma caps in order to limit burst Changes in v5: None Changes in v4: None Changes in v3: None Changes in v2: None Changes in v1: None drivers/spi/spi-rockchip.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 79a8bc4..aa9561f 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -199,6 +199,7 @@ struct rockchip_spi { struct sg_table rx_sg; struct rockchip_spi_dma_data dma_rx; struct rockchip_spi_dma_data dma_tx; + struct dma_slave_caps dma_caps; }; static inline void spi_enable_chip(struct rockchip_spi *rs, int enable) @@ -449,7 +450,10 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi *rs) rxconf.direction = rs->dma_rx.direction; rxconf.src_addr = rs->dma_rx.addr; rxconf.src_addr_width = rs->n_bytes; - rxconf.src_maxburst = rs->n_bytes; + if (rs->dma_caps.max_burst > 4) + rxconf.src_maxburst = 4; + else + rxconf.src_maxburst = 1; dmaengine_slave_config(rs->dma_rx.ch, &rxconf); rxdesc = dmaengine_prep_slave_sg( @@ -466,7 +470,10 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi *rs) txconf.direction = rs->dma_tx.direction; txconf.dst_addr = rs->dma_tx.addr; txconf.dst_addr_width = rs->n_bytes; - txconf.dst_maxburst = rs->n_bytes; + if (rs->dma_caps.max_burst > 4) + txconf.dst_maxburst = 4; + else + txconf.dst_maxburst = 1; dmaengine_slave_config(rs->dma_tx.ch, &txconf); txdesc = dmaengine_prep_slave_sg( @@ -730,6 +737,7 @@ static int rockchip_spi_probe(struct platform_device *pdev) } if (rs->dma_tx.ch && rs->dma_rx.ch) { + dma_get_slave_caps(rs->dma_rx.ch, &(rs->dma_caps)); rs->dma_tx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_TXDR); rs->dma_rx.addr = (dma_addr_t)(mem->start + ROCKCHIP_SPI_RXDR); rs->dma_tx.direction = DMA_MEM_TO_DEV; -- 2.3.7