How to reset IPU when DMA does not terminate?

[adriancox]

I'm using the IPU on the IMX.6Q (silicon rev 1.2) to place an overlay on to video before encoding in the VPU. I have a number of other IPU tasks handling deinterlace, colour space conversion, and display.

After a period running, having submitted this IPU task successfully thousands of times, the application crashes. In this state, all other applications (including the IPU examples) fail with a timeout when they submit an IPU task. The problem is only cured by a reboot.

I think I now need advice on how to modify the IPU driver so that I can reset the relevant parts of the IPU when I detect this condition, ideally without disrupting the display. I'm not sure whether this is a kernel bug or silicon problem.

By inserting debug into the driver, I can tell the following about the state. This is my IPU task:

imx-ipuv3 imx-ipuv3.0: [0xbafbf000]input:
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     format = 0x32315559
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     width = 720
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     height = 576
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.w = 720
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.h = 576
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.pos.x = 0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.pos.y = 0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]input buffer:
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     paddr = 0x18000000
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     i_off = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     i_uoff = 0x65400
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     i_voff = 0x7e900
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     istride = 720
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]output:
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     format = 0x33424752
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     width = 720
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     height = 576
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.w = 720
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.h = 576
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.pos.x = 0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.pos.y = 0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     rotate = 0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]output buffer:
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     paddr = 0x18a00000
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     o_off = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     o_uoff = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     o_voff = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     ostride = 2160
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]overlay:
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     format = 0x41524742
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     width = 720
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     height = 576
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.w = 720
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.h = 576
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.pos.x = 0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     crop.pos.y = 0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]overlay buffer:
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     paddr = 0x18e00000
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     ov_off = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     ov_uoff = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     ov_voff = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     ovstride = 2880
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]local alpha enabled with:
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     paddr = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     ov_alpha_off = 0x0
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     ov_alpha_stride = 720
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]want task_id = 1
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]want task mode is 0x1
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     IC_MODE = 0x1
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     ROT_MODE = 0x2
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     VDI_MODE = 0x4
imx-ipuv3 imx-ipuv3.0: [0xbafbf000]     Task_no = 0x740

These are the channel parameters:

imx-ipuv3 imx-ipuv3.0: ch 14 word 0 - 10000000 00003000 00000000 E0000000 0008FC59

imx-ipuv3 imx-ipuv3.0: ch 14 word 1 - 031C0000 00000000 20E3C000 FFF2CFC0 00006208

imx-ipuv3 imx-ipuv3.0: PFS 0x7,      

imx-ipuv3 imx-ipuv3.0: BPP 0x0,      

imx-ipuv3 imx-ipuv3.0: NPB 0xf      

imx-ipuv3 imx-ipuv3.0: FW 719,     

imx-ipuv3 imx-ipuv3.0: FH 575,       

imx-ipuv3 imx-ipuv3.0: EBA0 0x18e00000   

imx-ipuv3 imx-ipuv3.0: EBA1 0x0

imx-ipuv3 imx-ipuv3.0: Stride 2879   

imx-ipuv3 imx-ipuv3.0: scan_order 0

imx-ipuv3 imx-ipuv3.0: uv_stride 8712

imx-ipuv3 imx-ipuv3.0: u_offset 0x0

imx-ipuv3 imx-ipuv3.0: v_offset 0x0

imx-ipuv3 imx-ipuv3.0: Width0 7+1,

imx-ipuv3 imx-ipuv3.0: Width1 7+1,

imx-ipuv3 imx-ipuv3.0: Width2 7+1,

imx-ipuv3 imx-ipuv3.0: Width3 7+1,

imx-ipuv3 imx-ipuv3.0: Offset0 8,

imx-ipuv3 imx-ipuv3.0: Offset1 16,

imx-ipuv3 imx-ipuv3.0: Offset2 24,

imx-ipuv3 imx-ipuv3.0: Offset3 0

These are the IPU registers:

imx-ipuv3 imx-ipuv3.0: IPU_CONF =       0x00000004  

imx-ipuv3 imx-ipuv3.0: IDMAC_CONF =     0x0000002F

imx-ipuv3 imx-ipuv3.0: IDMAC_CHA_EN1 =  0x00205000

imx-ipuv3 imx-ipuv3.0: IDMAC_CHA_EN2 =  0x00000000

imx-ipuv3 imx-ipuv3.0: IDMAC_CHA_PRI1 =         0x18800001

imx-ipuv3 imx-ipuv3.0: IDMAC_CHA_PRI2 =         0x00000000

imx-ipuv3 imx-ipuv3.0: IDMAC_BAND_EN1 =         0x00000000

imx-ipuv3 imx-ipuv3.0: IDMAC_BAND_EN2 =         0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_CHA_DB_MODE_SEL0 =   0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_CHA_DB_MODE_SEL1 =   0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_CHA_TRB_MODE_SEL0 =  0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_CHA_TRB_MODE_SEL1 =  0x00000000

imx-ipuv3 imx-ipuv3.0: DMFC_WR_CHAN =   0x00000090

imx-ipuv3 imx-ipuv3.0: DMFC_WR_CHAN_DEF =       0x202020F6

imx-ipuv3 imx-ipuv3.0: DMFC_DP_CHAN =   0x00009694

imx-ipuv3 imx-ipuv3.0: DMFC_DP_CHAN_DEF =       0x2020F6F6

imx-ipuv3 imx-ipuv3.0: DMFC_IC_CTRL =   0x00000002

imx-ipuv3 imx-ipuv3.0: IPU_FS_PROC_FLOW1 =      0x80000000

imx-ipuv3 imx-ipuv3.0: IPU_FS_PROC_FLOW2 =      0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_FS_PROC_FLOW3 =      0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_FS_DISP_FLOW1 =      0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_VDIC_VDI_FSIZE =     0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_VDIC_VDI_C =         0x00000000

imx-ipuv3 imx-ipuv3.0: IPU_IC_CONF =    0x40000B00

[adriancox]

I have a workaround that greatly reduces the frequency of the lockup. This patch prevents the IPU driver executing two overlay operations at once - even though the operations should be independent, and I can find no suggestion in the datasheet that they might clash.

--- a/drivers/mxc/ipu3/ipu_device.c

+++ b/drivers/mxc/ipu3/ipu_device.c

@@ -327,6 +327,7 @@ struct ipu_channel_tabel {

  struct mutex lock;

  u8 used[MXC_IPU_MAX_NUM][MAX_PP_CH];

  u8 vdoa_used;

+ u8 overlay_used;

};

struct ipu_thread_data {

@@ -1171,6 +1172,10 @@ static int _get_vdoa_ipu_res(struct ipu_task_entry *t)

  goto out;

  }

  }

+

+ // Don't run two overlays at once. Don't know why

+ if (t->overlay_en && tbl->overlay_used)

+ goto out;

  for (i = 0; i < max_ipu_no; i++) {

  ipu = ipu_get_soc(i);

@@ -1229,6 +1234,8 @@ next:

  t->ipu = ipu;

  t->ipu_id = i;

  t->dev = ipu->dev;

+ if (t->overlay_en)

+ tbl->overlay_used = 1;

  if (atomic_inc_return(&t->res_get) == 2)

  dev_err(t->dev,

  "ERR no:0x%x,found_vdoa:%d,get ipu twice\n",

@@ -1269,6 +1276,8 @@ static void put_vdoa_ipu_res(struct ipu_task_entry *tsk, int vdoa_only)

  goto out;

  }

  }

+ if (tsk->overlay_en)

+ tbl->overlay_used = 0;

  tbl->used[tsk->ipu_id][tsk->task_id - 1] = 0;

  rel_ipu = 1;

--