On 03/12/2017 10:51 AM, Russell King - ARM Linux wrote:
I've just looked at my test system's dmesg, and spotted this in the log. It's been a while since these popped out of the kernel, so I don't know what caused them (other than the obvious, a media-ctl command.) My script which sets this up only enables links, and then configures the formats etc, and doesn't disable them, so I don't see why the power count should be going negative.
There's actually nothing preventing userland from disabling a link multiple times, and imx_media_link_notify() complies, and so csi_s_power(OFF) gets called multiple times, and so that WARN_ON() in there is silly, I borrowed this from other MC driver examples, but it makes no sense to me, I'll remove it and prevent the power count from going negative. Steve
------------[ cut here ]------------ WARNING: CPU: 1 PID: 1889 at drivers/staging/media/imx/imx-media-csi.c:806 csi_s_power+0x9c/0xa8 [imx_media_csi] Modules linked in: caam_jr uvcvideo snd_soc_imx_sgtl5000 snd_soc_fsl_asoc_card snd_soc_imx_spdif imx_media_csi(C) imx6_mipi_csi2(C) snd_soc_imx_audmux snd_soc_sgtl5000 imx219 imx_media_ic(C) imx_media_capture(C) imx_media_vdic(C) caam video_multiplexer imx_sdma coda v4l2_mem2mem videobuf2_v4l2 imx2_wdt imx_vdoa videobuf2_dma_contig videobuf2_core videobuf2_vmalloc videobuf2_memops snd_soc_fsl_ssi imx_thermal snd_soc_fsl_spdif imx_pcm_dma imx_media(C) imx_media_common(C) nfsd rc_pinnacle_pctv_hd dw_hdmi_ahb_audio dw_hdmi_cec etnaviv CPU: 1 PID: 1889 Comm: media-ctl Tainted: G C 4.11.0-rc1+ #2125 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<c0013ba4>] (dump_backtrace) from [<c0013de4>] (show_stack+0x18/0x1c) r6:600e0013 r5:ffffffff r4:00000000 r3:00000000 [<c0013dcc>] (show_stack) from [<c033f728>] (dump_stack+0xa4/0xdc) [<c033f684>] (dump_stack) from [<c00326cc>] (__warn+0xdc/0x108) r6:bf124014 r5:00000000 r4:00000000 r3:c09ea4a8 [<c00325f0>] (__warn) from [<c0032720>] (warn_slowpath_null+0x28/0x30) r10:ede00010 r8:ede4a348 r7:d039501c r6:d0395140 r5:00000000 r4:d0395010 [<c00326f8>] (warn_slowpath_null) from [<bf1229e0>] (csi_s_power+0x9c/0xa8 [imx_media_csi]) [<bf122944>] (csi_s_power [imx_media_csi]) from [<bf04a930>] (imx_media_set_power+0x3c/0x108 [imx_media_common]) r7:d039501c r6:00000000 r5:00000000 r4:0000000c [<bf04a8f4>] (imx_media_set_power [imx_media_common]) from [<bf04aa34>] (imx_media_pipeline_set_power+0x38/0x40 [imx_media_common]) r10:00000001 r9:00000001 r8:ede4a348 r7:ede00010 r6:ede4a348 r5:d039501c r4:00000001 [<bf04a9fc>] (imx_media_pipeline_set_power [imx_media_common]) from [<bf052148>] (imx_media_link_notify+0xf0/0x144 [imx_media]) r7:ede00010 r6:ed59f900 r5:00000000 r4:d039501c [<bf052058>] (imx_media_link_notify [imx_media]) from [<c04fa858>] (__media_entity_setup_link+0x110/0x1d8) r10:c0347c03 r9:d7eb3dc8 r8:befe92b0 r7:ede00010 r6:00000000 r5:00000001 r4:ed59f900 r3:bf052058 [<c04fa748>] (__media_entity_setup_link) from [<c04f9bb0>] (media_device_setup_link+0x84/0x90) r7:ede00010 r6:ede00010 r5:ef3fd810 r4:d7eb3dc8 [<c04f9b2c>] (media_device_setup_link) from [<c04f9e94>] (media_device_ioctl+0xa4/0x148) r6:00000000 r5:d7eb3dc8 r4:c077b014 r3:c04f9b2c [<c04f9df0>] (media_device_ioctl) from [<c04fa3a0>] (media_ioctl+0x38/0x4c) r10:ed5eca68 r9:d7eb2000 r8:befe92b0 r7:00000003 r6:00000003 r5:e82ca280 r4:c0190304 [<c04fa368>] (media_ioctl) from [<c018f9c0>] (do_vfs_ioctl+0x98/0x9a0) [<c018f928>] (do_vfs_ioctl) from [<c0190304>] (SyS_ioctl+0x3c/0x60) r10:00000000 r9:d7eb2000 r8:befe92b0 r7:00000003 r6:c0347c03 r5:e82ca280 r4:e82ca280 [<c01902c8>] (SyS_ioctl) from [<c000fd60>] (ret_fast_syscall+0x0/0x1c) r8:c000ff04 r7:00000036 r6:000261d0 r5:00000001 r4:009162e8 r3:00000001 ---[ end trace 4fdd40e5adfc4485 ]--- ------------[ cut here ]------------ WARNING: CPU: 1 PID: 1889 at drivers/staging/media/imx/imx-media-csi.c:806 csi_s_power+0x9c/0xa8 [imx_media_csi] Modules linked in: caam_jr uvcvideo snd_soc_imx_sgtl5000 snd_soc_fsl_asoc_card snd_soc_imx_spdif imx_media_csi(C) imx6_mipi_csi2(C) snd_soc_imx_audmux snd_soc_sgtl5000 imx219 imx_media_ic(C) imx_media_capture(C) imx_media_vdic(C) caam video_multiplexer imx_sdma coda v4l2_mem2mem videobuf2_v4l2 imx2_wdt imx_vdoa videobuf2_dma_contig videobuf2_core videobuf2_vmalloc videobuf2_memops snd_soc_fsl_ssi imx_thermal snd_soc_fsl_spdif imx_pcm_dma imx_media(C) imx_media_common(C) nfsd rc_pinnacle_pctv_hd dw_hdmi_ahb_audio dw_hdmi_cec etnaviv CPU: 1 PID: 1889 Comm: media-ctl Tainted: G WC 4.11.0-rc1+ #2125 Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) Backtrace: [<c0013ba4>] (dump_backtrace) from [<c0013de4>] (show_stack+0x18/0x1c) r6:600e0013 r5:ffffffff r4:00000000 r3:00000000 [<c0013dcc>] (show_stack) from [<c033f728>] (dump_stack+0xa4/0xdc) [<c033f684>] (dump_stack) from [<c00326cc>] (__warn+0xdc/0x108) r6:bf124014 r5:00000000 r4:00000000 r3:c09ea4a8 [<c00325f0>] (__warn) from [<c0032720>] (warn_slowpath_null+0x28/0x30) r10:ede00010 r8:ede4a348 r7:ee000800 r6:d0395140 r5:00000000 r4:d0395010 [<c00326f8>] (warn_slowpath_null) from [<bf1229e0>] (csi_s_power+0x9c/0xa8 [imx_media_csi]) [<bf122944>] (csi_s_power [imx_media_csi]) from [<bf04a930>] (imx_media_set_power+0x3c/0x108 [imx_media_common]) r7:ee000800 r6:00000000 r5:00000000 r4:0000000c [<bf04a8f4>] (imx_media_set_power [imx_media_common]) from [<bf04aa34>] (imx_media_pipeline_set_power+0x38/0x40 [imx_media_common]) r10:00000001 r9:00000001 r8:ede4a348 r7:ede00010 r6:ede4a348 r5:ee000800 r4:00000001 [<bf04a9fc>] (imx_media_pipeline_set_power [imx_media_common]) from [<bf052148>] (imx_media_link_notify+0xf0/0x144 [imx_media]) r7:ede00010 r6:d0320480 r5:ee000800 r4:ee000800 [<bf052058>] (imx_media_link_notify [imx_media]) from [<c04fa858>] (__media_entity_setup_link+0x110/0x1d8) r10:c0347c03 r9:d7eb3dc8 r8:befe92b0 r7:ede00010 r6:00000000 r5:00000001 r4:d0320480 r3:bf052058 [<c04fa748>] (__media_entity_setup_link) from [<c04f9bb0>] (media_device_setup_link+0x84/0x90) r7:ede00010 r6:ede00010 r5:d039501c r4:d7eb3dc8 [<c04f9b2c>] (media_device_setup_link) from [<c04f9e94>] (media_device_ioctl+0xa4/0x148) r6:00000000 r5:d7eb3dc8 r4:c077b014 r3:c04f9b2c [<c04f9df0>] (media_device_ioctl) from [<c04fa3a0>] (media_ioctl+0x38/0x4c) r10:ed5eca68 r9:d7eb2000 r8:befe92b0 r7:00000003 r6:00000003 r5:e82ca500 r4:c0190304 [<c04fa368>] (media_ioctl) from [<c018f9c0>] (do_vfs_ioctl+0x98/0x9a0) [<c018f928>] (do_vfs_ioctl) from [<c0190304>] (SyS_ioctl+0x3c/0x60) r10:00000000 r9:d7eb2000 r8:befe92b0 r7:00000003 r6:c0347c03 r5:e82ca500 r4:e82ca500 [<c01902c8>] (SyS_ioctl) from [<c000fd60>] (ret_fast_syscall+0x0/0x1c) r8:c000ff04 r7:00000036 r6:000261d0 r5:00000001 r4:0091737c r3:00000001 ---[ end trace 4fdd40e5adfc4486 ]---
