From 6e72eab2e7b7a157d554b8f9faed7676047be7c1 Mon Sep 17 00:00:00 2001
From: Nikhil Devshatwar <nikhil.nd@ti.com>
Date: Tue, 12 Nov 2019 15:53:33 +0100
Subject: [PATCH] media: ti-vpe: cal: Restrict DMA to avoid memory corruption
Git-commit: 6e72eab2e7b7a157d554b8f9faed7676047be7c1
Patch-mainline: v5.6-rc1
References: git-fixes

When setting DMA for video capture from CSI channel, if the DMA size
is not given, it ends up writing as much data as sent by the camera.

This may lead to overwriting the buffers causing memory corruption.
Observed green lines on the default framebuffer.

Restrict the DMA to maximum height as specified in the S_FMT ioctl.

Signed-off-by: Nikhil Devshatwar <nikhil.nd@ti.com>
Signed-off-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/platform/ti-vpe/cal.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/ti-vpe/cal.c b/drivers/media/platform/ti-vpe/cal.c
index 4f9a7609cb5f..eb3727ba185d 100644
--- a/drivers/media/platform/ti-vpe/cal.c
+++ b/drivers/media/platform/ti-vpe/cal.c
@@ -767,12 +767,13 @@ static void pix_proc_config(struct cal_ctx *ctx)
 }
 
 static void cal_wr_dma_config(struct cal_ctx *ctx,
-			      unsigned int width)
+			      unsigned int width, unsigned int height)
 {
 	u32 val;
 
 	val = reg_read(ctx->dev, CAL_WR_DMA_CTRL(ctx->csi2_port));
 	set_field(&val, ctx->csi2_port, CAL_WR_DMA_CTRL_CPORT_MASK);
+	set_field(&val, height, CAL_WR_DMA_CTRL_YSIZE_MASK);
 	set_field(&val, CAL_WR_DMA_CTRL_DTAG_PIX_DAT,
 		  CAL_WR_DMA_CTRL_DTAG_MASK);
 	set_field(&val, CAL_WR_DMA_CTRL_MODE_CONST,
@@ -1395,7 +1396,8 @@ static int cal_start_streaming(struct vb2_queue *vq, unsigned int count)
 	csi2_lane_config(ctx);
 	csi2_ctx_config(ctx);
 	pix_proc_config(ctx);
-	cal_wr_dma_config(ctx, ctx->v_fmt.fmt.pix.bytesperline);
+	cal_wr_dma_config(ctx, ctx->v_fmt.fmt.pix.bytesperline,
+			  ctx->v_fmt.fmt.pix.height);
 	cal_wr_dma_addr(ctx, addr);
 	csi2_ppi_enable(ctx);
 
-- 
2.16.4