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pobrn opened this issue Apr 24, 2025 · 1 comment
Open

vc_sm_cma: lockdep warnings while capturing from camera #6814

pobrn opened this issue Apr 24, 2025 · 1 comment

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@pobrn
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pobrn commented Apr 24, 2025

Describe the bug

dmabuf related lockdep warnings are emitted while capturing using libcamera

Steps to reproduce the behaviour

  1. enable lockdep in the kernel
  2. start cam -c1 -C (or similar)
  3. observe the lockdep warnings in dma_buf_{un,}map_attachment()

Device (s)

Raspberry Pi 4 Mod. B

System

  • Linux <hostname> 6.15.0-rc3-v8+ #2 SMP PREEMPT Thu Apr 24 18:47:39 CEST 2025 aarch64 GNU/Linux
  • rpi camera module 3 (imx708)

Logs

[   93.311225] ------------[ cut here ]------------
[   93.311240] WARNING: CPU: 1 PID: 325 at drivers/dma-buf/dma-buf.c:1125 dma_buf_map_attachment+0x94/0x160
[   93.325350] Modules linked in: vc4 snd_soc_hdmi_codec drm_exec drm_display_helper cec dw9807_vcm imx708 drm_client_lib drm_dma_helper v3d snd_soc_core bcm2835_codec(C) gpu_sched snd_compress bcm2835_v4l2(C) b
cm2835_isp(C) bcm2835_unicam_legacy drm_shmem_helper brcmfmac rpi_hevc_dec bcm2835_mmal_vchiq(C) drm_kms_helper v4l2_dv_timings snd_pcm_dmaengine snd_bcm2835(C) v4l2_fwnode drm v4l2_mem2mem vc_sm_cma(C) videobuf
2_vmalloc snd_pcm brcmutil v4l2_async videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 i2c_mux_pinctrl drm_panel_orientation_quirks raspberrypi_hwmon videodev snd_timer i2c_mux cfg80211 i2c_brcmstb snd i2c_b
cm2835 videobuf2_common backlight rfkill raspberrypi_gpiomem mc nvmem_rmem uio_pdrv_genirq uio sch_fq_codel fuse nfnetlink ipv6
[   93.391721] CPU: 1 UID: 0 PID: 325 Comm: cam Tainted: G        WC          6.15.0-rc3-v8+ #2 PREEMPT 
[   93.400939] Tainted: [W]=WARN, [C]=CRAP
[   93.404767] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
[   93.410593] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   93.417549] pc : dma_buf_map_attachment+0x94/0x160
[   93.422338] lr : dma_buf_map_attachment+0x90/0x160
[   93.427125] sp : ffff80008152b8d0
[   93.430432] x29: ffff80008152b8d0 x28: ffff5e7a086157f0 x27: ffff80008152bc08
[   93.437570] x26: ffffc3af18a34000 x25: 00000000070a2e00 x24: ffff80008152ba10
[   93.444707] x23: ffff5e7a00fb5780 x22: 0000000000000000 x21: 0000000000000000
[   93.451843] x20: 0000000000000000 x19: ffff5e7a070a2e00 x18: 0000000000000000
[   93.458979] x17: 0000000000000000 x16: ffffc3af55c30888 x15: 0000ffff762ae300
[   93.466116] x14: 0000000400000000 x13: 0000000000000000 x12: ffffc3af57241e40
[   93.473252] x11: ffffc3af5755dc90 x10: ffffc3af567b536c x9 : ffffc3af55308d18
[   93.480388] x8 : ffff5e7a0721ab80 x7 : ffffc3af56885000 x6 : 0000000000000000
[   93.487524] x5 : 0000000000000004 x4 : 0000000000000000 x3 : ffff5e7a0721ab80
[   93.494660] x2 : ffff9acb64db2000 x1 : 0000000000000000 x0 : 0000000000000000
[   93.501797] Call trace:
[   93.504237]  dma_buf_map_attachment+0x94/0x160 (P)
[   93.509027]  vc_sm_cma_import_dmabuf_internal+0xc8/0x448 [vc_sm_cma]
[   93.515391]  vc_sm_cma_import_dmabuf+0x60/0xf8 [vc_sm_cma]
[   93.520877]  vchiq_mmal_submit_buffer+0xc4/0x190 [bcm2835_mmal_vchiq]
[   93.527321]  bcm2835_isp_node_buffer_queue+0xa4/0x130 [bcm2835_isp]
[   93.533589]  __enqueue_in_driver+0x78/0x160 [videobuf2_common]
[   93.539434]  vb2_core_qbuf+0x440/0x670 [videobuf2_common]
[   93.544839]  vb2_qbuf+0xb8/0x1a0 [videobuf2_v4l2]
[   93.549549]  vb2_ioctl_qbuf+0x68/0x80 [videobuf2_v4l2]
[   93.554689]  v4l_qbuf+0x50/0x80 [videodev]
[   93.558835]  __video_do_ioctl+0x410/0x4a0 [videodev]
[   93.563836]  video_usercopy+0x2f4/0x890 [videodev]
[   93.568662]  video_ioctl2+0x20/0x50 [videodev]
[   93.573141]  v4l2_ioctl+0x48/0x78 [videodev]
[   93.577445]  __arm64_sys_ioctl+0xbc/0x100
[   93.581454]  invoke_syscall+0x50/0x120
[   93.585199]  el0_svc_common.constprop.0+0xc8/0xf0
[   93.589899]  do_el0_svc+0x24/0x38
[   93.593209]  el0_svc+0x48/0x110
[   93.596348]  el0t_64_sync_handler+0x10c/0x140
[   93.600702]  el0t_64_sync+0x198/0x1a0
[   93.604360] irq event stamp: 217930
[   93.607841] hardirqs last  enabled at (217929): [<ffffc3af555f822c>] ___slab_alloc+0x594/0xfb8
[   93.616451] hardirqs last disabled at (217930): [<ffffc3af5612d694>] el1_dbg+0x24/0x90
[   93.624364] softirqs last  enabled at (217908): [<ffffc3af55e28610>] vchiq_release_internal+0xc0/0x138
[   93.633670] softirqs last disabled at (217906): [<ffffc3af55e285cc>] vchiq_release_internal+0x7c/0x138
[   93.642974] ---[ end trace 0000000000000000 ]---

[  201.704425] ------------[ cut here ]------------
[  201.704449] WARNING: CPU: 2 PID: 325 at drivers/dma-buf/dma-buf.c:1228 dma_buf_unmap_attachment+0xd8/0xe8
[  201.718682] Modules linked in: vc4 snd_soc_hdmi_codec drm_exec drm_display_helper cec dw9807_vcm imx708 drm_client_lib drm_dma_helper v3d snd_soc_core bcm2835_codec(C) gpu_sched snd_compress bcm2835_v4l2(C) b
cm2835_isp(C) bcm2835_unicam_legacy drm_shmem_helper brcmfmac rpi_hevc_dec bcm2835_mmal_vchiq(C) drm_kms_helper v4l2_dv_timings snd_pcm_dmaengine snd_bcm2835(C) v4l2_fwnode drm v4l2_mem2mem vc_sm_cma(C) videobuf
2_vmalloc snd_pcm brcmutil v4l2_async videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 i2c_mux_pinctrl drm_panel_orientation_quirks raspberrypi_hwmon videodev snd_timer i2c_mux cfg80211 i2c_brcmstb snd i2c_b
cm2835 videobuf2_common backlight rfkill raspberrypi_gpiomem mc nvmem_rmem uio_pdrv_genirq uio sch_fq_codel fuse nfnetlink ipv6
[  201.785300] CPU: 2 UID: 0 PID: 325 Comm: cam Tainted: G        WC          6.15.0-rc3-v8+ #2 PREEMPT 
[  201.794534] Tainted: [W]=WARN, [C]=CRAP
[  201.798372] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
[  201.804207] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  201.811176] pc : dma_buf_unmap_attachment+0xd8/0xe8
[  201.816069] lr : dma_buf_unmap_attachment+0xd4/0xe8
[  201.820960] sp : ffff80008152bcc0
[  201.824276] x29: ffff80008152bcc0 x28: ffff5e7a0721ab80 x27: 0000000000000000
[  201.831436] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000
[  201.838592] x23: ffffc3af55665380 x22: ffffc3af55665314 x21: 0000000000000000
[  201.845749] x20: ffff5e7a02d35ac0 x19: ffff5e7a07070b80 x18: 0000000000000000
[  201.852904] x17: 0000000000000000 x16: ffffc3af55c30a90 x15: ffff80008152bcc8
[  201.860059] x14: 0000000000000028 x13: 0000000000011919 x12: ffffc3af5720b020
[  201.867214] x11: ffffc3af5755dc90 x10: ffffc3af567b536c x9 : ffffc3af55308d18
[  201.874370] x8 : ffff80008152bb30 x7 : 0000000000000000 x6 : ffff80008152bbf0
[  201.881524] x5 : ffff80008152bb70 x4 : 0000000000000000 x3 : ffff5e7a0721ab80
[  201.888678] x2 : ffff9acb64dd5000 x1 : 0000000000000000 x0 : 0000000000000000
[  201.895833] Call trace:
[  201.898282]  dma_buf_unmap_attachment+0xd8/0xe8 (P)
[  201.903176]  vc_sm_dma_buf_release+0x7c/0x158 [vc_sm_cma]
[  201.908610]  dma_buf_release+0x48/0xb0
[  201.912371]  __dentry_kill+0xe8/0x210
[  201.916048]  dput.part.0+0x204/0x3e8
[  201.919633]  dput+0x1c/0x38
[  201.922436]  __fput+0x130/0x308
[  201.925589]  ____fput+0x1c/0x30
[  201.928740]  task_work_run+0x88/0x100
[  201.932416]  do_notify_resume+0x15c/0x180
[  201.936440]  el0_svc+0x108/0x110
[  201.939681]  el0t_64_sync_handler+0x10c/0x140
[  201.944050]  el0t_64_sync+0x198/0x1a0
[  201.947719] irq event stamp: 222528
[  201.951208] hardirqs last  enabled at (222527): [<ffffc3af5614043c>] _raw_spin_unlock_irqrestore+0x74/0x80
[  201.960878] hardirqs last disabled at (222528): [<ffffc3af5612d694>] el1_dbg+0x24/0x90
[  201.968805] softirqs last  enabled at (222344): [<ffffc3af552c8d90>] handle_softirqs+0x448/0x4a0
[  201.977602] softirqs last disabled at (222319): [<ffffc3af552102c4>] __do_softirq+0x1c/0x28
[  201.985959] ---[ end trace 0000000000000000 ]---

Additional context

No response
@pobrn
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pobrn commented Apr 25, 2025

The following seems to work so far:

diff --git a/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c b/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
index 4ebe909d7d97..8609d6ec7657 100644
--- a/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
+++ b/drivers/staging/vc04_services/vc-sm-cma/vc_sm.c
@@ -249,9 +244,9 @@ static void vc_sm_clean_up_dmabuf(struct vc_sm_buffer *buffer)
 
        /* Handle cleaning up imported dmabufs */
        if (buffer->import.sgt) {
-               dma_buf_unmap_attachment(buffer->import.attach,
-                                        buffer->import.sgt,
-                                        DMA_BIDIRECTIONAL);
+               dma_buf_unmap_attachment_unlocked(buffer->import.attach,
+                                                 buffer->import.sgt,
+                                                 DMA_BIDIRECTIONAL);
                buffer->import.sgt = NULL;
        }
        if (buffer->import.attach) {
@@ -735,7 +730,7 @@ vc_sm_cma_import_dmabuf_internal(struct vc_sm_privdata_t *private,
                goto error;
        }
 
-       sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+       sgt = dma_buf_map_attachment_unlocked(attach, DMA_BIDIRECTIONAL);
        if (IS_ERR(sgt)) {
                ret = PTR_ERR(sgt);
                goto error;
@@ -845,7 +840,7 @@ vc_sm_cma_import_dmabuf_internal(struct vc_sm_privdata_t *private,
        free_kernel_id(import.kernel_id);
        kfree(buffer);
        if (sgt)
-               dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
+               dma_buf_unmap_attachment_unlocked(attach, sgt, DMA_BIDIRECTIONAL);
        if (attach)
                dma_buf_detach(dma_buf, attach);
        dma_buf_put(dma_buf);

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