Dear Guennadi
> Hm, ok, maybe I can ask you about one more test, if you don't mind. The
> thing is, you only see the problem, if after the ->active buffer has been
> freed in free_buffer(), your DMA engine continues writing to the freed
> memory, but you only notice this, if some other driver manages to grab and
> use it in this time, then its data is going to be overwritten.
(snip)
> Best would be to first try all three loops without the patch from Magnus
> and see if any of them triggers. And use a larger frame (maximum that your
> sensor can deliver) to give the DMA engine more time per frame.
Hmm. maybe I could understand...
OK.
I tested with MigoR + ov772x + following way.
1) apply patch to kernel
> diff -u a/drivers/media/video/sh_mobile_ceu_camera.c
> b/drivers/media/video/sh_mobile_ceu_camera.c
> --- a/drivers/media/video/sh_mobile_ceu_camera.c
> +++ b/drivers/media/video/sh_mobile_ceu_camera.c
> @@ -326,6 +326,7 @@
> spin_lock_irqsave(&pcdev->lock, flags);
>
> vb = pcdev->active;
> + WARN_ON(vb->state == VIDEOBUF_NEEDS_INIT);
> list_del_init(&vb->queue);
>
> if (!list_empty(&pcdev->capture))
2) apply patch to capture-example
I think your wanting to say is this...
diff -u capture_example.c capture_example.c.test
--- capture_example.c 2009-01-24 09:35:12.000000000 +0900
+++ capture_example.c.test 2009-02-19 18:09:32.000000000 +0900
@@ -590,6 +590,8 @@
int main(int argc, char **argv)
{
+ int i;
+
dev_name = "/dev/video0";
for (;;) {
@@ -648,11 +650,14 @@
}
open_device();
- init_device();
- start_capturing();
- mainloop();
- stop_capturing();
- uninit_device();
+ for (i=0 ; i<100 ; i++) {
+ printf("%d ", i);
+ init_device();
+ start_capturing();
+ mainloop();
+ stop_capturing();
+ uninit_device();
+ }
close_device();
fprintf(stderr, "\n");
return 0;
3) test this capture_example.
Then, It say
======================================================================
camera 0-0: SuperH Mobile CEU driver attached to camera 0
camera_host0: Format 0 not found
.0 ... camera_host0: Format 0 not found
------------[ cut here ]------------
Badness at 8c141b9e [verbose debug info unavailable]
Pid : 869, Comm: c2
CPU : 0 Not tainted (2.6.29-rc4-00197-g41480ae-dirty #801)
PC is at sh_mobile_ceu_irq+0x2a/0xc8
PR is at handle_IRQ_event+0x2e/0x68
PC : 8c141b9e SP : 8fe15e40 SR : 400001f1 TEA : 2961ba40
R0 : 8ff05afc R1 : 00000000 R2 : 8fe14000 R3 : 00000000
R4 : 8ff05a00 R5 : 8ff05a00 R6 : 00000010 R7 : 00000000
R8 : 8ff416e0 R9 : 000000f0 R10 : 00000000 R11 : 00000034
R12 : 8ff414d0 R13 : 8ff3a1e0 R14 : 8ff89e74
MACH: 00000000 MACL: 00000c30 GBR : 29686450 PR : 8c030e0a
Call trace:
[<8c030e0a>] handle_IRQ_event+0x2e/0x68
[<8c0326a8>] handle_level_irq+0x6c/0x100
[<8c00356c>] do_IRQ+0x34/0x5c
[<8c007118>] ret_from_irq+0x0/0x10
[<8c003538>] do_IRQ+0x0/0x5c
[<8c0f2c44>] memset+0x30/0x4c
[<8c00b25a>] dma_alloc_coherent+0x5e/0x148
[<8c141742>] __videobuf_mmap_mapper+0xbe/0x1a4
[<8c13fb88>] videobuf_mmap_mapper+0x3c/0x70
[<8c050ad8>] mmap_region+0x184/0x34c
[<8c005234>] old_mmap+0x60/0xa8
[<8c007266>] syscall_call+0xc/0x10
[<8c0051d4>] old_mmap+0x0/0xa8
camera 0-0: SuperH Mobile CEU driver detached from camera 0
Trace/breakpoint trap
======================================================================
4) apply Magnus patch
5) and test it again
then It say...
========================================================
-bash-3.00# ./c2 -d /dev/video0 -f -c 4
camera 0-0: SuperH Mobile CEU driver attached to camera 0
camera_host0: Format 0 not found
.0 ... camera_host0: Format 0 not found
.1 ... camera_host0: Format 0 not found
.2 ... camera_host0: Format 0 not found
.3 ... camera_host0: Format 0 not found
(snip)
.96 ... camera_host0: Format 0 not found
.97 ... camera_host0: Format 0 not found
.98 ... camera_host0: Format 0 not found
.99 ...camera 0-0: SuperH Mobile CEU driver detached from camera 0
========================================================
Best regards
--
Kuninori Morimoto
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