Re: [PATCH 17/18] media/omap3isp: Clean up IOMMU workaround

[Sakari Ailus]

Hi Robin,

On Thu, Aug 20, 2020 at 04:08:36PM +0100, Robin Murphy wrote:
> Now that arch/arm is wired up for default domains and iommu-dma, devices
> behind IOMMUs will get mappings set up automatically as appropriate, so
> there is no need for drivers to do so manually.
> 
> Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>

Thanks for the patch.

I haven't looked at the details but it seems that this causes the buffer
memory allocation to be physically contiguous, which causes a failure to
allocate video buffers of entirely normal size. I guess that was not
intentional?

-----------------8<---------------------------
[  218.934448] WARNING: CPU: 0 PID: 1994 at mm/page_alloc.c:4859 __alloc_pages_nodemask+0x9c/0xb1c
[  218.943847] Modules linked in: omap3_isp videobuf2_dma_contig videobuf2_memops videobuf2_v4l2 videobuf2_common leds_as3645a smiapp v4l2_flash_led_class led_class_flash v4l2_fwnode smiapp_pll videodev leds_gpio mc led_class
[  218.964660] CPU: 0 PID: 1994 Comm: yavta Not tainted 5.9.0-rc1-dirty #1818
[  218.972442] Hardware name: Generic OMAP36xx (Flattened Device Tree)
[  218.978973] Backtrace: 
[  218.981842] [<c010bf90>] (dump_backtrace) from [<c010c350>] (show_stack+0x20/0x24)
[  218.989715]  r7:00000000 r6:00000009 r5:c08f03bc r4:c08f2fef
[  218.995880] [<c010c330>] (show_stack) from [<c03d3328>] (dump_stack+0x28/0x30)
[  219.003631] [<c03d3300>] (dump_stack) from [<c012e324>] (__warn+0x100/0x118)
[  219.010955]  r5:c08f03bc r4:00000000
[  219.014953] [<c012e224>] (__warn) from [<c012e6f4>] (warn_slowpath_fmt+0x84/0xa8)
[  219.022949]  r9:c0232090 r8:c08f03bc r7:c0b08a88 r6:00000009 r5:000012fb r4:00000000
[  219.031036] [<c012e674>] (warn_slowpath_fmt) from [<c0232090>] (__alloc_pages_nodemask+0x9c/0xb1c)
[  219.040557]  r9:c0185c3c r8:00000000 r7:010ec000 r6:00000000 r5:0000000d r4:00000000
[  219.048858] [<c0231ff4>] (__alloc_pages_nodemask) from [<c01108f0>] (__dma_alloc_buffer.constprop.14+0x3c/0x90)
[  219.059570]  r10:00000cc0 r9:c0185c3c r8:00000000 r7:010ec000 r6:0000000d r5:c0b08a88
[  219.067901]  r4:00000cc0
[  219.070587] [<c01108b4>] (__dma_alloc_buffer.constprop.14) from [<c0110a6c>] (remap_allocator_alloc+0x34/0x7c)
[  219.081207]  r9:c0185c3c r8:00000247 r7:e6d7fb84 r6:010ec000 r5:c0b08a88 r4:00000001
[  219.089263] [<c0110a38>] (remap_allocator_alloc) from [<c010f4f4>] (__dma_alloc+0x124/0x21c)
[  219.098236]  r9:ed99fc10 r8:e69aa890 r7:00000000 r6:ffffffff r5:c0b08a88 r4:e6fdd680
[  219.106536] [<c010f3d0>] (__dma_alloc) from [<c010f69c>] (arm_dma_alloc+0x68/0x74)
[  219.114654]  r10:00000cc0 r9:c0185c3c r8:00000cc0 r7:e69aa890 r6:010ec000 r5:ed99fc10
[  219.122985]  r4:00000000
[  219.125671] [<c010f634>] (arm_dma_alloc) from [<c0185c3c>] (dma_alloc_attrs+0xe4/0x120)
[  219.134216]  r9:00000000 r8:e69aa890 r7:010ec000 r6:c0b08a88 r5:ed99fc10 r4:c010f634
[  219.142517] [<c0185b58>] (dma_alloc_attrs) from [<bf095c3c>] (vb2_dc_alloc+0xcc/0x108 [videobuf2_dma_contig])
[  219.153076]  r10:e6885ca8 r9:e6abfc48 r8:00000002 r7:00000000 r6:010ec000 r5:ed99fc10
[  219.161407]  r4:e69aa880
[  219.164184] [<bf095b70>] (vb2_dc_alloc [videobuf2_dma_contig]) from [<bf080fd0>] (__vb2_queue_alloc+0x258/0x4a4 [videobuf2_common])
[  219.176696]  r8:bf095b70 r7:010ec000 r6:00000000 r5:e6885ca8 r4:e6abfc00
[  219.183959] [<bf080d78>] (__vb2_queue_alloc [videobuf2_common]) from [<bf0833a0>] (vb2_core_reqbufs+0x408/0x498 [videobuf2_common])
[  219.196533]  r10:e6885ce8 r9:00000000 r8:e6d7fe24 r7:e6d7fcec r6:bf09ced4 r5:bf088580
[  219.204895]  r4:e6885ca8
[  219.207672] [<bf082f98>] (vb2_core_reqbufs [videobuf2_common]) from [<bf08e1cc>] (vb2_reqbufs+0x64/0x70 [videobuf2_v4l2])
[  219.219268]  r10:00000000 r9:bf032bc0 r8:c0145608 r7:bf0ad4a4 r6:e6885ca8 r5:00000000
[  219.227600]  r4:e6d7fe24
[  219.230499] [<bf08e168>] (vb2_reqbufs [videobuf2_v4l2]) from [<bf09d7b4>] (isp_video_reqbufs+0x40/0x54 [omap3_isp])
[  219.241607]  r7:bf0ad4a4 r6:e6d7fe24 r5:e6885c00 r4:e6cca928
[  219.247924] [<bf09d774>] (isp_video_reqbufs [omap3_isp]) from [<bf01de4c>] (v4l_reqbufs+0x4c/0x50 [videodev])
[  219.258514]  r7:bf0ad4a4 r6:e6885c00 r5:e6d7fe24 r4:e7efbec0
[  219.264984] [<bf01de00>] (v4l_reqbufs [videodev]) from [<bf01eeb4>] (__video_do_ioctl+0x2d8/0x414 [videodev])
[  219.275512]  r7:bf01de00 r6:00000000 r5:00000000 r4:e6cca2e0
[  219.281982] [<bf01ebdc>] (__video_do_ioctl [videodev]) from [<bf01fa1c>] (video_usercopy+0x144/0x508 [videodev])
[  219.292816]  r10:e7efbec0 r9:c0145608 r8:e6d7fe24 r7:00000000 r6:00000000 r5:bf01ebdc
[  219.300933]  r4:c0145608
[  219.304168] [<bf01f8d8>] (video_usercopy [videodev]) from [<bf01fdfc>] (video_ioctl2+0x1c/0x24 [videodev])
[  219.314453]  r10:e7fbfda0 r9:e7efbec0 r8:00000003 r7:00000000 r6:bee658f4 r5:c0145608
[  219.322784]  r4:e7efbec0
[  219.325775] [<bf01fde0>] (video_ioctl2 [videodev]) from [<bf01814c>] (v4l2_ioctl+0x50/0x64 [videodev])
[  219.335845] [<bf0180fc>] (v4l2_ioctl [videodev]) from [<c02654a0>] (vfs_ioctl+0x30/0x44)
[  219.344482]  r7:00000000 r6:e7efbec0 r5:bee658f4 r4:c0145608
[  219.350402] [<c0265470>] (vfs_ioctl) from [<c0265e9c>] (sys_ioctl+0xdc/0x7ec)
[  219.358062] [<c0265dc0>] (sys_ioctl) from [<c0100080>] (ret_fast_syscall+0x0/0x28)
[  219.366149] Exception stack(0xe6d7ffa8 to 0xe6d7fff0)
[  219.371673] ffa0:                   00000000 bee65c1a 00000003 c0145608 bee658f4 00000001
[  219.380157] ffc0: 00000000 bee65c1a 00000000 00000036 000009a0 00000000 0000ef30 010eb400
[  219.388885] ffe0: 0001716c bee65104 0000b588 b6e413ac
[  219.394409]  r10:00000036 r9:e6d7e000 r8:c0100244 r7:00000036 r6:00000000 r5:bee65c1a
[  219.402740]  r4:00000000
[  219.405426] irq event stamp: 5075
[  219.408905] hardirqs last  enabled at (5083): [<c01778b0>] console_unlock+0x4cc/0x524
[  219.417297] hardirqs last disabled at (5092): [<c01777ac>] console_unlock+0x3c8/0x524
[  219.425628] softirqs last  enabled at (4532): [<c01017d8>] __do_softirq+0x1f0/0x490
[  219.433837] softirqs last disabled at (4493): [<c0132c20>] irq_exit+0xe4/0x160
[  219.441558] ---[ end trace 8c56810633cf24db ]---
[  219.446502] omap3isp 480bc000.isp: dma_alloc_coherent of size 17743872 failed
-----------------8<---------------------------

-- 
Kind regards,

Sakari Ailus