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From:   Nikita Yushchenko <nikita.yoush@cogentembedded.com>
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
        Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Koji Matsuoka <koji.matsuoka.xm@renesas.com>,
        Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Subject: [PATCH] media: vsp1: mask interrupts before enabling
Date:   Sun, 26 Sep 2021 18:53:56 +0300
Message-Id: <20210926155356.23861-1-nikita.yoush@cogentembedded.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Setting up VSP interrupt handler without masking interrupt before causes
interrupt handler to be immediately called (and crash due to null pointer
dereference) on r8a77951-ulcb-kf board.

Fix that by explicitly masking all interrupts before setting the interrupt
handler. To do so, have to set the interrupt handler later, after hw
revision is already detected and number of interrupts to mask gets
known.

Based on patch by Koji Matsuoka <koji.matsuoka.xm@renesas.com> included
in the Renesas BSP kernel. Updated that to use wfp_count as the number of
WPF interrupts to mask.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
---
 drivers/media/platform/vsp1/vsp1_drv.c | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/media/platform/vsp1/vsp1_drv.c b/drivers/media/platform/vsp1/vsp1_drv.c
index de442d6c9926..0e9a6fad54f8 100644
--- a/drivers/media/platform/vsp1/vsp1_drv.c
+++ b/drivers/media/platform/vsp1/vsp1_drv.c
@@ -811,13 +811,6 @@ static int vsp1_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	ret = devm_request_irq(&pdev->dev, irq->start, vsp1_irq_handler,
-			      IRQF_SHARED, dev_name(&pdev->dev), vsp1);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "failed to request IRQ\n");
-		return ret;
-	}
-
 	/* FCP (optional). */
 	fcp_node = of_parse_phandle(pdev->dev.of_node, "renesas,fcp", 0);
 	if (fcp_node) {
@@ -847,7 +840,6 @@ static int vsp1_probe(struct platform_device *pdev)
 		goto done;
 
 	vsp1->version = vsp1_read(vsp1, VI6_IP_VERSION);
-	vsp1_device_put(vsp1);
 
 	for (i = 0; i < ARRAY_SIZE(vsp1_device_infos); ++i) {
 		if ((vsp1->version & VI6_IP_VERSION_MODEL_MASK) ==
@@ -861,11 +853,26 @@ static int vsp1_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "unsupported IP version 0x%08x\n",
 			vsp1->version);
 		ret = -ENXIO;
+		vsp1_device_put(vsp1);
 		goto done;
 	}
 
 	dev_dbg(&pdev->dev, "IP version 0x%08x\n", vsp1->version);
 
+	for (i = 0; i < vsp1->info->lif_count; ++i)
+		vsp1_write(vsp1, VI6_DISP_IRQ_ENB(i), 0);
+	for (i = 0; i < vsp1->info->wpf_count; ++i)
+		vsp1_write(vsp1, VI6_WPF_IRQ_ENB(i), 0);
+
+	vsp1_device_put(vsp1);
+
+	ret = devm_request_irq(&pdev->dev, irq->start, vsp1_irq_handler,
+			       IRQF_SHARED, dev_name(&pdev->dev), vsp1);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to request IRQ\n");
+		goto done;
+	}
+
 	/* Instantiate entities. */
 	ret = vsp1_create_entities(vsp1);
 	if (ret < 0) {
-- 
2.30.2