Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Message-ID: <8736xrkrci.wl%kuninori.morimoto.gx@renesas.com>
From:   Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Subject: [PATCH v2] dmaengine: rcar-dmac: don't use DMAC error interrupt
User-Agent: Wanderlust/2.15.9 Emacs/24.3 Mule/6.0
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     <vkoul@kernel.org>, Dan Williams <dan.j.williams@intel.com>,
        Magnus Damm <magnus.damm@gmail.com>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Kieran Bingham <kieran@ksquared.org.uk>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        <dmaengine@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=US-ASCII
Date:   Wed, 13 Jun 2018 08:49:22 +0000
Received-SPF: None (protection.outlook.com: renesas.com does not designate
 permitted sender hosts)
SpamDiagnosticOutput: 1:99
SpamDiagnosticMetadata: NSPM
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Jun 2018 08:49:22.7076 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: e0bb4343-0490-45e6-75e8-08d5d10a8f64
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 53d82571-da19-47e4-9cb4-625a166a4a2a
X-MS-Exchange-Transport-CrossTenantHeadersStamped: TYAPR01MB2080
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org


From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

Current rcar-dmac is using DMAC error interrupt which will handle all
channel's error. But in this design, error handling itself will be
issue if user want to use virtualization, multi OS, etc.
This patch removes current DMAC error interrupt handling, and handle it
on each channel interrupt handler.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
[Kuninori: updated patch to adjust DMACHCR/DMAOR]
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Nguyen Viet Dung <nv-dung@jinso.co.jp>
---
v1 -> v2

 - add [Kuninori: xxx] line on git log
 - don't remove DT property
 - tidyup rcar_dmac_isr_channel()

 .../devicetree/bindings/dma/renesas,rcar-dmac.txt  |  1 +
 drivers/dma/sh/rcar-dmac.c                         | 72 +++++++---------------
 2 files changed, 23 insertions(+), 50 deletions(-)

diff --git a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt
index b1ba6395..b8e1c13 100644
--- a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt
+++ b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt
@@ -38,6 +38,7 @@ Required Properties:
 - interrupt-names: one entry for the error interrupt, named "error", plus one
   entry per channel, named "ch%u", where %u is the channel number ranging from
   zero to the number of channels minus one.
+  # "error" interrupt will be ignored, so far
 
 - clock-names: "fck" for the functional clock
 - clocks: a list of phandle + clock-specifier pairs, one for each entry
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 2a2ccd9..279c930 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -431,7 +431,8 @@ static void rcar_dmac_chan_start_xfer(struct rcar_dmac_chan *chan)
 		chcr |= RCAR_DMACHCR_DPM_DISABLED | RCAR_DMACHCR_IE;
 	}
 
-	rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr | RCAR_DMACHCR_DE);
+	rcar_dmac_chan_write(chan, RCAR_DMACHCR,
+			     chcr | RCAR_DMACHCR_DE | RCAR_DMACHCR_CAIE);
 }
 
 static int rcar_dmac_init(struct rcar_dmac *dmac)
@@ -783,7 +784,8 @@ static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan)
 	u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
 
 	chcr &= ~(RCAR_DMACHCR_DSE | RCAR_DMACHCR_DSIE | RCAR_DMACHCR_IE |
-		  RCAR_DMACHCR_TE | RCAR_DMACHCR_DE);
+		  RCAR_DMACHCR_TE | RCAR_DMACHCR_DE |
+		  RCAR_DMACHCR_CAE | RCAR_DMACHCR_CAIE);
 	rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr);
 	rcar_dmac_chcr_de_barrier(chan);
 }
@@ -812,12 +814,7 @@ static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan)
 	}
 }
 
-static void rcar_dmac_stop(struct rcar_dmac *dmac)
-{
-	rcar_dmac_write(dmac, RCAR_DMAOR, 0);
-}
-
-static void rcar_dmac_abort(struct rcar_dmac *dmac)
+static void rcar_dmac_stop_all_chan(struct rcar_dmac *dmac)
 {
 	unsigned int i;
 
@@ -829,11 +826,10 @@ static void rcar_dmac_abort(struct rcar_dmac *dmac)
 		spin_lock(&chan->lock);
 		rcar_dmac_chan_halt(chan);
 		spin_unlock(&chan->lock);
-
-		rcar_dmac_chan_reinit(chan);
 	}
 }
 
+
 /* -----------------------------------------------------------------------------
  * Descriptors preparation
  */
@@ -1522,11 +1518,18 @@ static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev)
 	u32 mask = RCAR_DMACHCR_DSE | RCAR_DMACHCR_TE;
 	struct rcar_dmac_chan *chan = dev;
 	irqreturn_t ret = IRQ_NONE;
+	bool reinit = false;
 	u32 chcr;
 
 	spin_lock(&chan->lock);
 
 	chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
+	if (chcr & RCAR_DMACHCR_CAE) {
+		rcar_dmac_chan_halt(chan);
+		reinit = true;
+		goto spin_lock_end;
+	}
+
 	if (chcr & RCAR_DMACHCR_TE)
 		mask |= RCAR_DMACHCR_DE;
 	rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr & ~mask);
@@ -1539,8 +1542,16 @@ static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev)
 	if (chcr & RCAR_DMACHCR_TE)
 		ret |= rcar_dmac_isr_transfer_end(chan);
 
+spin_lock_end:
 	spin_unlock(&chan->lock);
 
+	if (reinit) {
+		dev_err(chan->chan.device->dev, "Channel Address Error\n");
+
+		rcar_dmac_chan_reinit(chan);
+		ret = IRQ_HANDLED;
+	}
+
 	return ret;
 }
 
@@ -1597,24 +1608,6 @@ static irqreturn_t rcar_dmac_isr_channel_thread(int irq, void *dev)
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t rcar_dmac_isr_error(int irq, void *data)
-{
-	struct rcar_dmac *dmac = data;
-
-	if (!(rcar_dmac_read(dmac, RCAR_DMAOR) & RCAR_DMAOR_AE))
-		return IRQ_NONE;
-
-	/*
-	 * An unrecoverable error occurred on an unknown channel. Halt the DMAC,
-	 * abort transfers on all channels, and reinitialize the DMAC.
-	 */
-	rcar_dmac_stop(dmac);
-	rcar_dmac_abort(dmac);
-	rcar_dmac_init(dmac);
-
-	return IRQ_HANDLED;
-}
-
 /* -----------------------------------------------------------------------------
  * OF xlate and channel filter
  */
@@ -1784,8 +1777,6 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 	struct rcar_dmac *dmac;
 	struct resource *mem;
 	unsigned int i;
-	char *irqname;
-	int irq;
 	int ret;
 
 	dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
@@ -1824,17 +1815,6 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 	if (IS_ERR(dmac->iomem))
 		return PTR_ERR(dmac->iomem);
 
-	irq = platform_get_irq_byname(pdev, "error");
-	if (irq < 0) {
-		dev_err(&pdev->dev, "no error IRQ specified\n");
-		return -ENODEV;
-	}
-
-	irqname = devm_kasprintf(dmac->dev, GFP_KERNEL, "%s:error",
-				 dev_name(dmac->dev));
-	if (!irqname)
-		return -ENOMEM;
-
 	/* Enable runtime PM and initialize the device. */
 	pm_runtime_enable(&pdev->dev);
 	ret = pm_runtime_get_sync(&pdev->dev);
@@ -1885,14 +1865,6 @@ static int rcar_dmac_probe(struct platform_device *pdev)
 			goto error;
 	}
 
-	ret = devm_request_irq(&pdev->dev, irq, rcar_dmac_isr_error, 0,
-			       irqname, dmac);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to request IRQ %u (%d)\n",
-			irq, ret);
-		return ret;
-	}
-
 	/* Register the DMAC as a DMA provider for DT. */
 	ret = of_dma_controller_register(pdev->dev.of_node, rcar_dmac_of_xlate,
 					 NULL);
@@ -1932,7 +1904,7 @@ static void rcar_dmac_shutdown(struct platform_device *pdev)
 {
 	struct rcar_dmac *dmac = platform_get_drvdata(pdev);
 
-	rcar_dmac_stop(dmac);
+	rcar_dmac_stop_all_chan(dmac);
 }
 
 static const struct of_device_id rcar_dmac_of_ids[] = {
-- 
1.9.1