[PATCH v4 7/7] spi: imx: defer spi initialization, if DMA engine is pending

Path	csiph.com!fu-berlin.de!bofh.it!news.nic.it!robomod
From	Anton Bondarenko <anton.bondarenko.sama@gmail.com>
Newsgroups	linux.kernel
Subject	[PATCH v4 7/7] spi: imx: defer spi initialization, if DMA engine is pending
Date	Sat, 28 Nov 2015 00:20:02 +0100
Message-ID	<qzAt4-MY-19@gated-at.bofh.it> (permalink)
References	<qzAt4-MY-3@gated-at.bofh.it>
X-Original-To	broonie@kernel.org, b38343@freescale.com, s.hauer@pengutronix.de
Dkim-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=DBiPWf8A/48vmXTEsU8rncoV7dFdBIiaEL0TypyE+W4=; b=TJBP/Nusn0Ycvogzq87fn532z3eBTXgMDF2P95Z2j8gQq5gkEqLTZYoeEL+yRmf2Nx /dPz5d5cGdk++Zgj293GvakoiXuMX1qiCoTm9od8/98Sxkau+kmSri/rJNTOHkcUx7uS 4bkh/FGURPsk3Z1I5+KEbOFSK2CXfvJYsh4xCI7eshZR2xKZdC1tgE0Zzm2rt3yGYHnZ RwCyyzaG+8R9IeQJDi3BzJ5rxihQk2nHFt4crbFu7AatKgsCwsCE1+7sfVadXcNHa+5A UcvWTRkQyuC1Hp9jMOw3FeYHoHEA6cXQfLxhTthOWvXDctA2bOFZoS+PxJlnMfnVMGln qLHA==
X-Received	by 10.112.54.229 with SMTP id m5mr21386509lbp.125.1448666176535; Fri, 27 Nov 2015 15:16:16 -0800 (PST)
X-Mailer	git-send-email 2.6.3
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	42
Organization	linux.* mail to news gateway
X-Original-Cc	linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, vladimir_zapolskiy@mentor.com, jiada_wang@mentor.com
X-Original-Date	Sat, 28 Nov 2015 00:16:05 +0100
X-Original-Message-ID	<1448666165-7473-8-git-send-email-anton.bondarenko.sama@gmail.com>
X-Original-References	<1448666165-7473-1-git-send-email-anton.bondarenko.sama@gmail.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1279037

Show key headers only | View raw

If SPI device supports DMA mode, but DMA controller is not yet
available due to e.g. a delay in the corresponding kernel module
initialization, retry to initialize SPI driver later on instead of
falling back into PIO only mode.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
---
 drivers/spi/spi-imx.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index aaa32c2..c2edd0f 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1341,9 +1341,15 @@ static int spi_imx_probe(struct platform_device *pdev)
 	 * Only validated on i.mx6 now, can remove the constrain if validated on
 	 * other chips.
 	 */
-	if (is_imx51_ecspi(spi_imx) &&
-	    spi_imx_sdma_init(&pdev->dev, spi_imx, master))
-		dev_err(&pdev->dev, "dma setup error,use pio instead\n");
+	if (is_imx51_ecspi(spi_imx)) {
+		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master);
+		if (ret == -EPROBE_DEFER)
+			goto out_clk_put;
+
+		if (ret < 0)
+			dev_err(&pdev->dev, "dma setup error %d, use pio\n",
+				ret);
+	}
 
 	spi_imx->devtype_data->reset(spi_imx);
 
-- 
2.6.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

[PATCH v4 0/7]  Improvements for SPI IMX driver for Freescale IMX51, IMX53 and IMX6 Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 3/7] spi: imx: add support for all SPI word width for DMA transfer Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 1/7] spi: imx: Fix DMA transfer Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
    Re: [PATCH v4 1/7] spi: imx: Fix DMA transfer Sascha Hauer <s.hauer@pengutronix.de> - 2015-11-30 09:30 +0100
  [PATCH v4 7/7] spi: imx: defer spi initialization, if DMA engine is pending Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 2/7] spi: imx: replace fixed timeout with calculated one Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 6/7] spi: imx: return error from dma channel request Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 5/7] spi: imx: Add support for loopback for ECSPI controllers Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100

csiph-web