From patchwork Tue Sep 6 07:58:34 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomoya X-Patchwork-Id: 1125682 Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p8680UjE019539 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Tue, 6 Sep 2011 08:00:53 GMT Received: from localhost ([127.0.0.1] helo=sfs-ml-3.v29.ch3.sourceforge.com) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1R0qa4-0007wC-R2; Tue, 06 Sep 2011 08:00:28 +0000 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1R0qa3-0007w6-W6 for spi-devel-general@lists.sourceforge.net; Tue, 06 Sep 2011 08:00:27 +0000 X-ACL-Warn: Received: from sm-d311v.smileserver.ne.jp ([203.211.202.206]) by sog-mx-1.v43.ch3.sourceforge.com with esmtp (Exim 4.76) id 1R0qa2-0002At-1n for spi-devel-general@lists.sourceforge.net; Tue, 06 Sep 2011 08:00:27 +0000 X-Virus-Status: clean(F-Secure/virusgw_smtp/403/viruscheck1-00.private.hosting-pf.net) Received: from localhost.localdomain (113x35x143x224.ap113.ftth.ucom.ne.jp [113.35.143.224]) by sm-d311v.smileserver.ne.jp (mail) with ESMTPSA id C449796DAF; Tue, 6 Sep 2011 17:00:19 +0900 (JST) From: Tomoya MORINAGA To: Grant Likely , spi-devel-general@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: [PATCH 5/5] spi-topcliff-pch: Fix overrun issue Date: Tue, 6 Sep 2011 16:58:34 +0900 Message-Id: <1315295914-6862-5-git-send-email-tomoya-linux@dsn.okisemi.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1315295914-6862-1-git-send-email-tomoya-linux@dsn.okisemi.com> References: <1315295914-6862-1-git-send-email-tomoya-linux@dsn.okisemi.com> X-Spam-Score: 0.0 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. X-Headers-End: 1R0qa2-0002At-1n Cc: qi.wang@intel.com, yong.y.wang@intel.com, Tomoya MORINAGA , toshiharu-linux@dsn.okisemi.com, kok.howg.ewe@intel.com, joel.clark@intel.com X-BeenThere: spi-devel-general@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Linux SPI core/device drivers discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: spi-devel-general-bounces@lists.sourceforge.net X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Tue, 06 Sep 2011 08:00:53 +0000 (UTC) We found that adding load, Rx data sometimes drops.(with DMA transfer mode) The cause is that before starting Rx-DMA processing, Tx-DMA processing starts. This causes FIFO overrun occurs. This patch fixes the issue by modifying FIFO tx-threshold and DMA descriptor size like below. Current this patch Rx-descriptor 4Byte+12Byte*341 --> 12Byte*340-4Byte-12Byte Rx-threshold (Not modified) Tx-descriptor 4Byte+12Byte*341 --> 16Byte-12Byte*340 Rx-threshold 12Byte --> 2Byte Signed-off-by: Tomoya MORINAGA --- drivers/spi/spi-topcliff-pch.c | 28 +++++++++++++++++++++++----- 1 files changed, 23 insertions(+), 5 deletions(-) diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c index 5be1142..c02fa62 100644 --- a/drivers/spi/spi-topcliff-pch.c +++ b/drivers/spi/spi-topcliff-pch.c @@ -50,6 +50,8 @@ #define PCH_RX_THOLD 7 #define PCH_RX_THOLD_MAX 15 +#define PCH_TX_THOLD 2 + #define PCH_MAX_BAUDRATE 5000000 #define PCH_MAX_FIFO_DEPTH 16 @@ -1043,8 +1045,7 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw) /* set receive fifo threshold and transmit fifo threshold */ pch_spi_setclr_reg(data->master, PCH_SPCR, ((size - 1) << SPCR_RFIC_FIELD) | - ((PCH_MAX_FIFO_DEPTH - PCH_DMA_TRANS_SIZE) << - SPCR_TFIC_FIELD), + (PCH_TX_THOLD << SPCR_TFIC_FIELD), MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS); spin_unlock_irqrestore(&data->lock, flags); @@ -1055,13 +1056,20 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw) /* offset, length setting */ sg = dma->sg_rx_p; for (i = 0; i < num; i++, sg++) { - if (i == 0) { - sg->offset = 0; + if (i == (num - 2)) { + sg->offset = size * i; + sg->offset = sg->offset * (*bpw / 8); sg_set_page(sg, virt_to_page(dma->rx_buf_virt), rem, sg->offset); sg_dma_len(sg) = rem; + } else if (i == (num - 1)) { + sg->offset = size * (i - 1) + rem; + sg->offset = sg->offset * (*bpw / 8); + sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size, + sg->offset); + sg_dma_len(sg) = size; } else { - sg->offset = rem + size * (i - 1); + sg->offset = size * i; sg->offset = sg->offset * (*bpw / 8); sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size, sg->offset); @@ -1085,6 +1093,16 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw) dma->desc_rx = desc_rx; /* TX */ + if (data->bpw_len > PCH_DMA_TRANS_SIZE) { + num = data->bpw_len / PCH_DMA_TRANS_SIZE; + size = PCH_DMA_TRANS_SIZE; + rem = 16; + } else { + num = 1; + size = data->bpw_len; + rem = data->bpw_len; + } + dma->sg_tx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC); sg_init_table(dma->sg_tx_p, num); /* Initialize SG table */ /* offset, length setting */