From patchwork Wed Jul 25 06:20:29 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shubhrajyoti Datta X-Patchwork-Id: 1235631 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 62303DFFC0 for ; Wed, 25 Jul 2012 06:20:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932817Ab2GYGUn (ORCPT ); Wed, 25 Jul 2012 02:20:43 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:43712 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932736Ab2GYGUm (ORCPT ); Wed, 25 Jul 2012 02:20:42 -0400 Received: from dbdp20.itg.ti.com ([172.24.170.38]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id q6P6KZ3o015552; Wed, 25 Jul 2012 01:20:35 -0500 Received: from DBDE70.ent.ti.com (localhost [127.0.0.1]) by dbdp20.itg.ti.com (8.13.8/8.13.8) with ESMTP id q6P6KXE3008139; Wed, 25 Jul 2012 11:50:34 +0530 (IST) Received: from dbdp32.itg.ti.com (172.24.170.251) by dbde70.ent.ti.com (172.24.170.148) with Microsoft SMTP Server id 14.1.323.3; Wed, 25 Jul 2012 11:50:33 +0530 Received: from ula0393217.india.ti.com (smtpvbd.itg.ti.com [172.24.170.250]) by dbdp32.itg.ti.com (8.13.8/8.13.8) with ESMTP id q6P6KWBx020301; Wed, 25 Jul 2012 11:50:33 +0530 From: Shubhrajyoti D To: CC: , , Shubhrajyoti D Subject: [PATCH] spi: omap2-mcspi: In case of dma errors fall back to pio Date: Wed, 25 Jul 2012 11:50:29 +0530 Message-ID: <1343197229-15188-1-git-send-email-shubhrajyoti@ti.com> X-Mailer: git-send-email 1.7.5.4 MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org In case there are dma errors currently the driver exits. Make the spi driver fall back to pio mode in case of dma errors. If the DMA engine is not selected the driver exits.This patch makes the spi fall back to pio in that case. Also adds a field dma_unusable to struct omap2_mcspi. Signed-off-by: Shubhrajyoti D Acked-by: Philip, Avinash --- drivers/spi/spi-omap2-mcspi.c | 21 +++++++++++++-------- 1 files changed, 13 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index bc47781..f243a39 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -129,6 +129,7 @@ struct omap2_mcspi { struct omap2_mcspi_dma *dma_channels; struct device *dev; struct omap2_mcspi_regs ctx; + int dma_unusable; }; struct omap2_mcspi_cs { @@ -845,7 +846,7 @@ static int omap2_mcspi_setup(struct spi_device *spi) if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) { ret = omap2_mcspi_request_dma(spi); if (ret < 0) - return ret; + mcspi->dma_unusable = 1; } ret = omap2_mcspi_enable_clocks(mcspi); @@ -956,7 +957,8 @@ static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m) __raw_writel(0, cs->base + OMAP2_MCSPI_TX0); - if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES) + if (!mcspi->dma_unusable && (m->is_dma_mapped || + t->len >= DMA_MIN_BYTES)) count = omap2_mcspi_txrx_dma(spi, t); else count = omap2_mcspi_txrx_pio(spi, t); @@ -1030,7 +1032,8 @@ static int omap2_mcspi_transfer_one_message(struct spi_master *master, return -EINVAL; } - if (m->is_dma_mapped || len < DMA_MIN_BYTES) + if (mcspi->dma_unusable || m->is_dma_mapped || + len < DMA_MIN_BYTES) continue; if (tx_buf != NULL) { @@ -1054,6 +1057,7 @@ static int omap2_mcspi_transfer_one_message(struct spi_master *master, return -EINVAL; } } + } omap2_mcspi_work(mcspi, m); @@ -1216,9 +1220,12 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev) mcspi->dma_channels[i].dma_tx_sync_dev = dma_res->start; } - if (status < 0) - goto dma_chnl_free; - + if (status < 0) { + dev_err(&pdev->dev, "cannot get DMA channel switching to pio\n"); + mcspi->dma_unusable = 1; + status = 0; + kfree(mcspi->dma_channels); + } pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT); pm_runtime_enable(&pdev->dev); @@ -1229,14 +1236,12 @@ static int __devinit omap2_mcspi_probe(struct platform_device *pdev) status = spi_register_master(master); if (status < 0) goto err_spi_register; - return status; err_spi_register: spi_master_put(master); disable_pm: pm_runtime_disable(&pdev->dev); -dma_chnl_free: kfree(mcspi->dma_channels); free_master: kfree(master);