6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Guoniu Zhou guoniu.zhou@nxp.com
[ Upstream commit 178aa3360220231dd91e7dbc2eb984525886c9c1 ]
If streamon/streamoff calls are imbalanced, such as when exiting an application with Ctrl+C when streaming, the m2m usage_count will never reach zero and the ISI channel won't be freed. Besides from that, if the input line width is more than 2K, it will trigger a WARN_ON():
[ 59.222120] ------------[ cut here ]------------ [ 59.226758] WARNING: drivers/media/platform/nxp/imx8-isi/imx8-isi-hw.c:631 at mxc_isi_channel_chain+0xa4/0x120, CPU#4: v4l2-ctl/654 [ 59.238569] Modules linked in: ap1302 [ 59.242231] CPU: 4 UID: 0 PID: 654 Comm: v4l2-ctl Not tainted 6.16.0-rc4-next-20250704-06511-gff0e002d480a-dirty #258 PREEMPT [ 59.253597] Hardware name: NXP i.MX95 15X15 board (DT) [ 59.258720] pstate: 80400009 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 59.265669] pc : mxc_isi_channel_chain+0xa4/0x120 [ 59.270358] lr : mxc_isi_channel_chain+0x44/0x120 [ 59.275047] sp : ffff8000848c3b40 [ 59.278348] x29: ffff8000848c3b40 x28: ffff0000859b4c98 x27: ffff800081939f00 [ 59.285472] x26: 000000000000000a x25: ffff0000859b4cb8 x24: 0000000000000001 [ 59.292597] x23: ffff0000816f4760 x22: ffff0000816f4258 x21: ffff000084ceb780 [ 59.299720] x20: ffff000084342ff8 x19: ffff000084340000 x18: 0000000000000000 [ 59.306845] x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffffdb369e1c [ 59.313969] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [ 59.321093] x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 [ 59.328217] x8 : ffff8000848c3d48 x7 : ffff800081930b30 x6 : ffff800081930b30 [ 59.335340] x5 : ffff0000859b6000 x4 : ffff80008193ae80 x3 : ffff800081022420 [ 59.342464] x2 : ffff0000852f6900 x1 : 0000000000000001 x0 : ffff000084341000 [ 59.349590] Call trace: [ 59.352025] mxc_isi_channel_chain+0xa4/0x120 (P) [ 59.356722] mxc_isi_m2m_streamon+0x160/0x20c [ 59.361072] v4l_streamon+0x24/0x30 [ 59.364556] __video_do_ioctl+0x40c/0x4a0 [ 59.368560] video_usercopy+0x2bc/0x690 [ 59.372382] video_ioctl2+0x18/0x24 [ 59.375857] v4l2_ioctl+0x40/0x60 [ 59.379168] __arm64_sys_ioctl+0xac/0x104 [ 59.383172] invoke_syscall+0x48/0x104 [ 59.386916] el0_svc_common.constprop.0+0xc0/0xe0 [ 59.391613] do_el0_svc+0x1c/0x28 [ 59.394915] el0_svc+0x34/0xf4 [ 59.397966] el0t_64_sync_handler+0xa0/0xe4 [ 59.402143] el0t_64_sync+0x198/0x19c [ 59.405801] ---[ end trace 0000000000000000 ]---
Address this issue by moving the streaming preparation and cleanup to the vb2 .prepare_streaming() and .unprepare_streaming() operations. This also simplifies the driver by allowing direct usage of the v4l2_m2m_ioctl_streamon() and v4l2_m2m_ioctl_streamoff() helpers.
Fixes: cf21f328fcaf ("media: nxp: Add i.MX8 ISI driver") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250821135123.29462-1-laurent.pinchart@ideasonboa... Signed-off-by: Guoniu Zhou guoniu.zhou@nxp.com Co-developed-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com Tested-by: Guoniu Zhou guoniu.zhou@nxp.com Reviewed-by: Frank Li Frank.Li@nxp.com Signed-off-by: Hans Verkuil hverkuil+cisco@kernel.org [ Adjust context ] Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c | 224 ++++++++------------- 1 file changed, 92 insertions(+), 132 deletions(-)
--- a/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c +++ b/drivers/media/platform/nxp/imx8-isi/imx8-isi-m2m.c @@ -43,7 +43,6 @@ struct mxc_isi_m2m_ctx_queue_data { struct v4l2_pix_format_mplane format; const struct mxc_isi_format_info *info; u32 sequence; - bool streaming; };
struct mxc_isi_m2m_ctx { @@ -236,6 +235,65 @@ static void mxc_isi_m2m_vb2_buffer_queue v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf); }
+static int mxc_isi_m2m_vb2_prepare_streaming(struct vb2_queue *q) +{ + struct mxc_isi_m2m_ctx *ctx = vb2_get_drv_priv(q); + const struct v4l2_pix_format_mplane *out_pix = &ctx->queues.out.format; + const struct v4l2_pix_format_mplane *cap_pix = &ctx->queues.cap.format; + const struct mxc_isi_format_info *cap_info = ctx->queues.cap.info; + const struct mxc_isi_format_info *out_info = ctx->queues.out.info; + struct mxc_isi_m2m *m2m = ctx->m2m; + int ret; + + guard(mutex)(&m2m->lock); + + if (m2m->usage_count == INT_MAX) + return -EOVERFLOW; + + /* + * Acquire the pipe and initialize the channel with the first user of + * the M2M device. + */ + if (m2m->usage_count == 0) { + bool bypass = cap_pix->width == out_pix->width && + cap_pix->height == out_pix->height && + cap_info->encoding == out_info->encoding; + + ret = mxc_isi_channel_acquire(m2m->pipe, + &mxc_isi_m2m_frame_write_done, + bypass); + if (ret) + return ret; + + mxc_isi_channel_get(m2m->pipe); + } + + m2m->usage_count++; + + /* + * Allocate resources for the channel, counting how many users require + * buffer chaining. + */ + if (!ctx->chained && out_pix->width > MXC_ISI_MAX_WIDTH_UNCHAINED) { + ret = mxc_isi_channel_chain(m2m->pipe); + if (ret) + goto err_deinit; + + m2m->chained_count++; + ctx->chained = true; + } + + return 0; + +err_deinit: + if (--m2m->usage_count == 0) { + mxc_isi_channel_put(m2m->pipe); + mxc_isi_channel_release(m2m->pipe); + } + + return ret; +} + static int mxc_isi_m2m_vb2_start_streaming(struct vb2_queue *q, unsigned int count) { @@ -265,6 +323,35 @@ static void mxc_isi_m2m_vb2_stop_streami } }
+static void mxc_isi_m2m_vb2_unprepare_streaming(struct vb2_queue *q) +{ + struct mxc_isi_m2m_ctx *ctx = vb2_get_drv_priv(q); + struct mxc_isi_m2m *m2m = ctx->m2m; + + guard(mutex)(&m2m->lock); + + /* + * If the last context is this one, reset it to make sure the device + * will be reconfigured when streaming is restarted. + */ + if (m2m->last_ctx == ctx) + m2m->last_ctx = NULL; + + /* Free the channel resources if this is the last chained context. */ + if (ctx->chained && --m2m->chained_count == 0) + mxc_isi_channel_unchain(m2m->pipe); + ctx->chained = false; + + /* Turn off the light with the last user. */ + if (--m2m->usage_count == 0) { + mxc_isi_channel_disable(m2m->pipe); + mxc_isi_channel_put(m2m->pipe); + mxc_isi_channel_release(m2m->pipe); + } + + WARN_ON(m2m->usage_count < 0); +} + static const struct vb2_ops mxc_isi_m2m_vb2_qops = { .queue_setup = mxc_isi_m2m_vb2_queue_setup, .buf_init = mxc_isi_m2m_vb2_buffer_init, @@ -272,8 +359,10 @@ static const struct vb2_ops mxc_isi_m2m_ .buf_queue = mxc_isi_m2m_vb2_buffer_queue, .wait_prepare = vb2_ops_wait_prepare, .wait_finish = vb2_ops_wait_finish, + .prepare_streaming = mxc_isi_m2m_vb2_prepare_streaming, .start_streaming = mxc_isi_m2m_vb2_start_streaming, .stop_streaming = mxc_isi_m2m_vb2_stop_streaming, + .unprepare_streaming = mxc_isi_m2m_vb2_unprepare_streaming, };
static int mxc_isi_m2m_queue_init(void *priv, struct vb2_queue *src_vq, @@ -483,135 +572,6 @@ static int mxc_isi_m2m_s_fmt_vid(struct return 0; }
-static int mxc_isi_m2m_streamon(struct file *file, void *fh, - enum v4l2_buf_type type) -{ - struct mxc_isi_m2m_ctx *ctx = to_isi_m2m_ctx(fh); - struct mxc_isi_m2m_ctx_queue_data *q = mxc_isi_m2m_ctx_qdata(ctx, type); - const struct v4l2_pix_format_mplane *out_pix = &ctx->queues.out.format; - const struct v4l2_pix_format_mplane *cap_pix = &ctx->queues.cap.format; - const struct mxc_isi_format_info *cap_info = ctx->queues.cap.info; - const struct mxc_isi_format_info *out_info = ctx->queues.out.info; - struct mxc_isi_m2m *m2m = ctx->m2m; - int ret; - - if (q->streaming) - return 0; - - mutex_lock(&m2m->lock); - - if (m2m->usage_count == INT_MAX) { - ret = -EOVERFLOW; - goto unlock; - } - - /* - * Acquire the pipe and initialize the channel with the first user of - * the M2M device. - */ - if (m2m->usage_count == 0) { - bool bypass = cap_pix->width == out_pix->width && - cap_pix->height == out_pix->height && - cap_info->encoding == out_info->encoding; - - ret = mxc_isi_channel_acquire(m2m->pipe, - &mxc_isi_m2m_frame_write_done, - bypass); - if (ret) - goto unlock; - - mxc_isi_channel_get(m2m->pipe); - } - - m2m->usage_count++; - - /* - * Allocate resources for the channel, counting how many users require - * buffer chaining. - */ - if (!ctx->chained && out_pix->width > MXC_ISI_MAX_WIDTH_UNCHAINED) { - ret = mxc_isi_channel_chain(m2m->pipe); - if (ret) - goto deinit; - - m2m->chained_count++; - ctx->chained = true; - } - - /* - * Drop the lock to start the stream, as the .device_run() operation - * needs to acquire it. - */ - mutex_unlock(&m2m->lock); - ret = v4l2_m2m_ioctl_streamon(file, fh, type); - if (ret) { - /* Reacquire the lock for the cleanup path. */ - mutex_lock(&m2m->lock); - goto unchain; - } - - q->streaming = true; - - return 0; - -unchain: - if (ctx->chained && --m2m->chained_count == 0) - mxc_isi_channel_unchain(m2m->pipe); - ctx->chained = false; - -deinit: - if (--m2m->usage_count == 0) { - mxc_isi_channel_put(m2m->pipe); - mxc_isi_channel_release(m2m->pipe); - } - -unlock: - mutex_unlock(&m2m->lock); - return ret; -} - -static int mxc_isi_m2m_streamoff(struct file *file, void *fh, - enum v4l2_buf_type type) -{ - struct mxc_isi_m2m_ctx *ctx = to_isi_m2m_ctx(fh); - struct mxc_isi_m2m_ctx_queue_data *q = mxc_isi_m2m_ctx_qdata(ctx, type); - struct mxc_isi_m2m *m2m = ctx->m2m; - - v4l2_m2m_ioctl_streamoff(file, fh, type); - - if (!q->streaming) - return 0; - - mutex_lock(&m2m->lock); - - /* - * If the last context is this one, reset it to make sure the device - * will be reconfigured when streaming is restarted. - */ - if (m2m->last_ctx == ctx) - m2m->last_ctx = NULL; - - /* Free the channel resources if this is the last chained context. */ - if (ctx->chained && --m2m->chained_count == 0) - mxc_isi_channel_unchain(m2m->pipe); - ctx->chained = false; - - /* Turn off the light with the last user. */ - if (--m2m->usage_count == 0) { - mxc_isi_channel_disable(m2m->pipe); - mxc_isi_channel_put(m2m->pipe); - mxc_isi_channel_release(m2m->pipe); - } - - WARN_ON(m2m->usage_count < 0); - - mutex_unlock(&m2m->lock); - - q->streaming = false; - - return 0; -} - static const struct v4l2_ioctl_ops mxc_isi_m2m_ioctl_ops = { .vidioc_querycap = mxc_isi_m2m_querycap,
@@ -632,8 +592,8 @@ static const struct v4l2_ioctl_ops mxc_i .vidioc_prepare_buf = v4l2_m2m_ioctl_prepare_buf, .vidioc_create_bufs = v4l2_m2m_ioctl_create_bufs,
- .vidioc_streamon = mxc_isi_m2m_streamon, - .vidioc_streamoff = mxc_isi_m2m_streamoff, + .vidioc_streamon = v4l2_m2m_ioctl_streamon, + .vidioc_streamoff = v4l2_m2m_ioctl_streamoff,
.vidioc_subscribe_event = v4l2_ctrl_subscribe_event, .vidioc_unsubscribe_event = v4l2_event_unsubscribe,