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From: Vignesh Raghavendra <vigneshr@ti.com>
To: Tudor Ambarus <tudor.ambarus@microchip.com>,
	Mark Brown <broonie@kernel.org>
Cc: Vignesh Raghavendra <vigneshr@ti.com>,
	Boris Brezillon <bbrezillon@kernel.org>,
	Ramuthevar Vadivel Murugan 
	<vadivel.muruganx.ramuthevar@linux.intel.com>,
	<linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
	<linux-spi@vger.kernel.org>, <simon.k.r.goldschmidt@gmail.com>,
	<dinguyen@kernel.org>, <marex@denx.de>
Subject: [PATCH v3 5/8] mtd: spi-nor: cadence-quadspi: Handle probe deferral while requesting DMA channel
Date: Mon, 1 Jun 2020 11:17:22 +0530	[thread overview]
Message-ID: <20200601054725.2060-6-vigneshr@ti.com> (raw)
In-Reply-To: <20200601054725.2060-1-vigneshr@ti.com>

dma_request_chan_by_mask() can throw EPROBE_DEFER if DMA provider
is not yet probed. Currently driver just falls back to using PIO mode
(which is less efficient) in this case. Instead return probe deferral
error as is so that driver will be re probed once DMA provider is
available.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 .../mtd/spi-nor/controllers/cadence-quadspi.c  | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/spi-nor/controllers/cadence-quadspi.c b/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
index 608ca657ff7f..0570ebca135a 100644
--- a/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
@@ -1169,7 +1169,7 @@ static void cqspi_controller_init(struct cqspi_st *cqspi)
 	cqspi_controller_enable(cqspi, 1);
 }
 
-static void cqspi_request_mmap_dma(struct cqspi_st *cqspi)
+static int cqspi_request_mmap_dma(struct cqspi_st *cqspi)
 {
 	dma_cap_mask_t mask;
 
@@ -1178,11 +1178,16 @@ static void cqspi_request_mmap_dma(struct cqspi_st *cqspi)
 
 	cqspi->rx_chan = dma_request_chan_by_mask(&mask);
 	if (IS_ERR(cqspi->rx_chan)) {
-		dev_err(&cqspi->pdev->dev, "No Rx DMA available\n");
+		int ret = PTR_ERR(cqspi->rx_chan);
+
+		if (ret != -EPROBE_DEFER)
+			dev_err(&cqspi->pdev->dev, "No Rx DMA available\n");
 		cqspi->rx_chan = NULL;
-		return;
+		return ret;
 	}
 	init_completion(&cqspi->rx_dma_complete);
+
+	return 0;
 }
 
 static const struct spi_nor_controller_ops cqspi_controller_ops = {
@@ -1269,8 +1274,11 @@ static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np)
 			dev_dbg(nor->dev, "using direct mode for %s\n",
 				mtd->name);
 
-			if (!cqspi->rx_chan)
-				cqspi_request_mmap_dma(cqspi);
+			if (!cqspi->rx_chan) {
+				ret = cqspi_request_mmap_dma(cqspi);
+				if (ret == -EPROBE_DEFER)
+					goto err;
+			}
 		}
 	}
 
-- 
2.26.2


WARNING: multiple messages have this Message-ID (diff)
From: Vignesh Raghavendra <vigneshr@ti.com>
To: Tudor Ambarus <tudor.ambarus@microchip.com>,
	Mark Brown <broonie@kernel.org>
Cc: marex@denx.de, Vignesh Raghavendra <vigneshr@ti.com>,
	Boris Brezillon <bbrezillon@kernel.org>,
	dinguyen@kernel.org, simon.k.r.goldschmidt@gmail.com,
	linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org,
	Ramuthevar Vadivel Murugan
	<vadivel.muruganx.ramuthevar@linux.intel.com>,
	linux-mtd@lists.infradead.org
Subject: [PATCH v3 5/8] mtd: spi-nor: cadence-quadspi: Handle probe deferral while requesting DMA channel
Date: Mon, 1 Jun 2020 11:17:22 +0530	[thread overview]
Message-ID: <20200601054725.2060-6-vigneshr@ti.com> (raw)
In-Reply-To: <20200601054725.2060-1-vigneshr@ti.com>

dma_request_chan_by_mask() can throw EPROBE_DEFER if DMA provider
is not yet probed. Currently driver just falls back to using PIO mode
(which is less efficient) in this case. Instead return probe deferral
error as is so that driver will be re probed once DMA provider is
available.

Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
---
 .../mtd/spi-nor/controllers/cadence-quadspi.c  | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/spi-nor/controllers/cadence-quadspi.c b/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
index 608ca657ff7f..0570ebca135a 100644
--- a/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/controllers/cadence-quadspi.c
@@ -1169,7 +1169,7 @@ static void cqspi_controller_init(struct cqspi_st *cqspi)
 	cqspi_controller_enable(cqspi, 1);
 }
 
-static void cqspi_request_mmap_dma(struct cqspi_st *cqspi)
+static int cqspi_request_mmap_dma(struct cqspi_st *cqspi)
 {
 	dma_cap_mask_t mask;
 
@@ -1178,11 +1178,16 @@ static void cqspi_request_mmap_dma(struct cqspi_st *cqspi)
 
 	cqspi->rx_chan = dma_request_chan_by_mask(&mask);
 	if (IS_ERR(cqspi->rx_chan)) {
-		dev_err(&cqspi->pdev->dev, "No Rx DMA available\n");
+		int ret = PTR_ERR(cqspi->rx_chan);
+
+		if (ret != -EPROBE_DEFER)
+			dev_err(&cqspi->pdev->dev, "No Rx DMA available\n");
 		cqspi->rx_chan = NULL;
-		return;
+		return ret;
 	}
 	init_completion(&cqspi->rx_dma_complete);
+
+	return 0;
 }
 
 static const struct spi_nor_controller_ops cqspi_controller_ops = {
@@ -1269,8 +1274,11 @@ static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np)
 			dev_dbg(nor->dev, "using direct mode for %s\n",
 				mtd->name);
 
-			if (!cqspi->rx_chan)
-				cqspi_request_mmap_dma(cqspi);
+			if (!cqspi->rx_chan) {
+				ret = cqspi_request_mmap_dma(cqspi);
+				if (ret == -EPROBE_DEFER)
+					goto err;
+			}
 		}
 	}
 
-- 
2.26.2


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Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/

  parent reply	other threads:[~2020-06-01  5:48 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-01  5:47 [PATCH v3 0/8] mtd: spi-nor: Move cadence-qaudspi to spi-mem framework Vignesh Raghavendra
2020-06-01  5:47 ` Vignesh Raghavendra
2020-06-01  5:47 ` [PATCH v3 1/8] mtd: spi-nor: cadence-quadspi: Make driver independent of flash geometry Vignesh Raghavendra
2020-06-01  5:47   ` Vignesh Raghavendra
2020-06-01  5:47 ` [PATCH v3 2/8] mtd: spi-nor: cadence-quadspi: Provide a way to disable DAC mode Vignesh Raghavendra
2020-06-01  5:47   ` Vignesh Raghavendra
2020-06-01  5:47 ` [PATCH v3 3/8] mtd: spi-nor: cadence-quadspi: Don't initialize rx_dma_complete on failure Vignesh Raghavendra
2020-06-01  5:47   ` Vignesh Raghavendra
2020-06-01  5:47 ` [PATCH v3 4/8] mtd: spi-nor: cadence-quadspi: Fix error path on failure to acquire reset lines Vignesh Raghavendra
2020-06-01  5:47   ` Vignesh Raghavendra
2020-06-01  5:47 ` Vignesh Raghavendra [this message]
2020-06-01  5:47   ` [PATCH v3 5/8] mtd: spi-nor: cadence-quadspi: Handle probe deferral while requesting DMA channel Vignesh Raghavendra
2020-06-01  6:31   ` Tudor.Ambarus
2020-06-01  6:31     ` Tudor.Ambarus
2020-06-01  5:47 ` [PATCH v3 6/8] mtd: spi-nor: cadence-quadspi: Drop redundant WREN in erase path Vignesh Raghavendra
2020-06-01  5:47   ` Vignesh Raghavendra
2020-06-01  6:32   ` Tudor.Ambarus
2020-06-01  6:32     ` Tudor.Ambarus
2020-06-01  5:47 ` [PATCH v3 7/8] mtd: spi-nor: Convert cadence-quadspi to use spi-mem framework Vignesh Raghavendra
2020-06-01  5:47   ` Vignesh Raghavendra
2020-06-01  6:49   ` Tudor.Ambarus
2020-06-01  6:49     ` Tudor.Ambarus
2020-06-01  5:47 ` [PATCH v3 8/8] spi: Move cadence-quadspi driver to drivers/spi/ Vignesh Raghavendra
2020-06-01  5:47   ` Vignesh Raghavendra
2020-06-01  7:00   ` Tudor.Ambarus
2020-06-01  7:00     ` Tudor.Ambarus
2020-06-01  7:07     ` Vignesh Raghavendra
2020-06-01  7:07       ` Vignesh Raghavendra

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