From fd3bf280a0039ff5bd0f7254dc123a4df46828d5 Mon Sep 17 00:00:00 2001 From: Jai Luthra Date: Fri, 23 Feb 2024 13:53:02 +0530 Subject: [PATCH] media: ti: j721e-csi2rx: Fix races while restarting DMA BugLink: https://bugs.launchpad.net/bugs/2073603 [ Upstream commit ad79c9ecea5baa7b4f19677e4b1c881ed89b0c3b ] After the frame is submitted to DMA, it may happen that the submitted list is not updated soon enough, and the DMA callback is triggered before that. This can lead to kernel crashes, so move everything in a single lock/unlock section to prevent such races. Fixes: b4a3d877dc92 ("media: ti: Add CSI2RX support for J721E") Signed-off-by: Jai Luthra Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin Signed-off-by: Portia Stephens Signed-off-by: Roxana Nicolescu --- drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c index 59b30fc43144..c8c1fda73e53 100644 --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c @@ -762,15 +762,14 @@ static void ti_csi2rx_buffer_queue(struct vb2_buffer *vb) dev_warn(csi->dev, "Failed to drain DMA. Next frame might be bogus\n"); + spin_lock_irqsave(&dma->lock, flags); ret = ti_csi2rx_start_dma(csi, buf); if (ret) { - dev_err(csi->dev, "Failed to start DMA: %d\n", ret); - spin_lock_irqsave(&dma->lock, flags); vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_ERROR); dma->state = TI_CSI2RX_DMA_IDLE; spin_unlock_irqrestore(&dma->lock, flags); + dev_err(csi->dev, "Failed to start DMA: %d\n", ret); } else { - spin_lock_irqsave(&dma->lock, flags); list_add_tail(&buf->list, &dma->submitted); spin_unlock_irqrestore(&dma->lock, flags); }