From patchwork Fri Nov 21 13:44:32 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: ludovic.desroches@atmel.com X-Patchwork-Id: 413049 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 66404140187 for ; Sat, 22 Nov 2014 00:45:00 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758627AbaKUNo7 (ORCPT ); Fri, 21 Nov 2014 08:44:59 -0500 Received: from eusmtp01.atmel.com ([212.144.249.242]:18500 "EHLO eusmtp01.atmel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755540AbaKUNo6 (ORCPT ); Fri, 21 Nov 2014 08:44:58 -0500 Received: from ibiza.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.30) with Microsoft SMTP Server id 14.2.347.0; Fri, 21 Nov 2014 14:44:50 +0100 From: Ludovic Desroches To: , CC: , , , Ludovic Desroches Subject: [PATCH 2/2] i2c: at91: enable probe deferring on dma channel request Date: Fri, 21 Nov 2014 14:44:32 +0100 Message-ID: <1416577472-24542-2-git-send-email-ludovic.desroches@atmel.com> X-Mailer: git-send-email 2.0.3 In-Reply-To: <1416577472-24542-1-git-send-email-ludovic.desroches@atmel.com> References: <1416577472-24542-1-git-send-email-ludovic.desroches@atmel.com> MIME-Version: 1.0 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org If dma controller is not probed, defer i2c probe. Signed-off-by: Ludovic Desroches Reviewed-by: Arnd Bergmann --- Arnd, It's a combination of the first patch I sent and yours. As you said that my patch "looks wrong but actually it's ok" I didn't dare to add your signed-off-by. drivers/i2c/busses/i2c-at91.c | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c index b69ea9b..3e56d73 100644 --- a/drivers/i2c/busses/i2c-at91.c +++ b/drivers/i2c/busses/i2c-at91.c @@ -635,17 +635,17 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) slave_config.dst_maxburst = 1; slave_config.device_fc = false; - dma->chan_tx = dma_request_slave_channel(dev->dev, "tx"); - if (!dma->chan_tx) { - dev_err(dev->dev, "can't get a DMA channel for tx\n"); - ret = -EBUSY; + dma->chan_tx = dma_request_slave_channel_reason(dev->dev, "tx"); + if (IS_ERR(dma->chan_tx)) { + ret = PTR_ERR(dma->chan_tx); + dma->chan_tx = NULL; goto error; } - dma->chan_rx = dma_request_slave_channel(dev->dev, "rx"); - if (!dma->chan_rx) { - dev_err(dev->dev, "can't get a DMA channel for rx\n"); - ret = -EBUSY; + dma->chan_rx = dma_request_slave_channel_reason(dev->dev, "rx"); + if (IS_ERR(dma->chan_rx)) { + ret = PTR_ERR(dma->chan_rx); + dma->chan_rx = NULL; goto error; } @@ -666,6 +666,7 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) sg_init_table(&dma->sg, 1); dma->buf_mapped = false; dma->xfer_in_progress = false; + dev->use_dma = true; dev_info(dev->dev, "using %s (tx) and %s (rx) for DMA transfers\n", dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); @@ -673,7 +674,8 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) return ret; error: - dev_info(dev->dev, "can't use DMA\n"); + if (ret != -EPROBE_DEFER) + dev_info(dev->dev, "can't use DMA, error %d\n", ret); if (dma->chan_rx) dma_release_channel(dma->chan_rx); if (dma->chan_tx) @@ -742,8 +744,9 @@ static int at91_twi_probe(struct platform_device *pdev) clk_prepare_enable(dev->clk); if (dev->dev->of_node) { - if (at91_twi_configure_dma(dev, phy_addr) == 0) - dev->use_dma = true; + rc = at91_twi_configure_dma(dev, phy_addr); + if (rc == -EPROBE_DEFER) + return rc; } rc = of_property_read_u32(dev->dev->of_node, "clock-frequency",