Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759411AbcDBBEu (ORCPT ); Fri, 1 Apr 2016 21:04:50 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:54596 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932954AbcDBA5S (ORCPT ); Fri, 1 Apr 2016 20:57:18 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Addy ke , Shawn Lin , Heiko Stuebner , Olof Johansson , Doug Anderson , Sonny Rao , Caesar Wang , Vinod Koul , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 141/170] spi: rockchip: modify DMA max burst to 1 Date: Fri, 1 Apr 2016 17:53:47 -0700 Message-Id: <1459558456-24452-142-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1459558456-24452-1-git-send-email-kamal@canonical.com> References: <1459558456-24452-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2781 Lines: 75 3.19.8-ckt18 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Addy Ke commit 80abf8880cc6e1594c11b7c417f22dde60e25312 upstream. 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 Signed-off-by: Caesar Wang Signed-off-by: Vinod Koul Signed-off-by: Kamal Mostafa --- 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 daabbab..484abd9 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -198,6 +198,7 @@ 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) @@ -441,7 +442,10 @@ 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( @@ -457,7 +461,10 @@ 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( @@ -701,6 +708,7 @@ 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; -- 2.7.4