On Mon, Mar 10, 2014 at 4:17 PM, Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> wrote:
> On 03/10/2014 10:47 AM, Rob Clark wrote:
>>
>> msm.hang_debug=y will dump out current register values if the gpu locks
>> up, for easier debugging.
>>
>> Signed-off-by: Rob Clark <robdclark@xxxxxxxxx>
>> ---
>> drivers/gpu/drm/msm/adreno/a3xx_gpu.c | 34
>> ++++++++++++++++++++++++++++++++-
>> drivers/gpu/drm/msm/adreno/adreno_gpu.c | 18 +++++++++++++++++
>> drivers/gpu/drm/msm/adreno/adreno_gpu.h | 1 +
>> 3 files changed, 52 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
>> b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
>> index 461df93..8b6fb84 100644
>> --- a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
>> +++ b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
>> @@ -35,6 +35,12 @@
>> A3XX_INT0_CP_AHB_ERROR_HALT | \
>> A3XX_INT0_UCHE_OOB_ACCESS)
>>
>> +
>> +static bool hang_debug = false;
>> +MODULE_PARM_DESC(hang_debug, "Dump registers when hang is detected (can
>> be slow!)");
>> +module_param_named(hang_debug, hang_debug, bool, 0600);
>> +static void a3xx_dump(struct msm_gpu *gpu);
>> +
>> static struct platform_device *a3xx_pdev;
>>
>> static void a3xx_me_init(struct msm_gpu *gpu)
>> @@ -291,6 +297,9 @@ static int a3xx_hw_init(struct msm_gpu *gpu)
>>
>> static void a3xx_recover(struct msm_gpu *gpu)
>> {
>> + /* dump registers before resetting gpu, if enabled: */
>> + if (hang_debug)
>> + a3xx_dump(gpu);
>
>
> You will need to be careful here - not all the registers are suitable for
> reading back.
> On some flavors of A330 in particular some HLSQ registers reads will bring
> the system
> down. You can see the gory details in the KGSL driver. If this works for
> you for now
> great but fair warning that some cores might have different experiences.
>From what I've seen, certain types of GPU lockup (for example shader
const overrun), even on a320, leave things such that reading HLSQ
registers does bad things, which is why I don't enable the bootarg by
default.
If there is a way to *detect* when HLSQ is in a bad state and skip
those registers, that would be awesome. I guess I should have another
look at latest kgsl to see if there is some trick I missed.
Or otherwise I should probably make the bootarg a bitmask so you can
choose to enable/disable certain groups of registers.
>
>> gpu_write(gpu, REG_A3XX_RBBM_SW_RESET_CMD, 1);
>> gpu_read(gpu, REG_A3XX_RBBM_SW_RESET_CMD);
>> gpu_write(gpu, REG_A3XX_RBBM_SW_RESET_CMD, 0);
>> @@ -352,7 +361,6 @@ static irqreturn_t a3xx_irq(struct msm_gpu *gpu)
>> return IRQ_HANDLED;
>> }
>>
>> -#ifdef CONFIG_DEBUG_FS
>> static const unsigned int a3xx_registers[] = {
>> 0x0000, 0x0002, 0x0010, 0x0012, 0x0018, 0x0018, 0x0020, 0x0027,
>> 0x0029, 0x002b, 0x002e, 0x0033, 0x0040, 0x0042, 0x0050, 0x005c,
>> @@ -392,6 +400,7 @@ static const unsigned int a3xx_registers[] = {
>> 0x303c, 0x303c, 0x305e, 0x305f,
>> };
>>
>> +#ifdef CONFIG_DEBUG_FS
>> static void a3xx_show(struct msm_gpu *gpu, struct seq_file *m)
>> {
>> int i;
>> @@ -415,6 +424,29 @@ static void a3xx_show(struct msm_gpu *gpu, struct
>> seq_file *m)
>> }
>> #endif
>>
>> +/* would be nice to not have to duplicate the _show() stuff with
>> printk(): */
>> +static void a3xx_dump(struct msm_gpu *gpu)
>> +{
>> + int i;
>> +
>> + adreno_dump(gpu);
>> + printk("status: %08x\n",
>> + gpu_read(gpu, REG_A3XX_RBBM_STATUS));
>> +
>> + /* dump these out in a form that can be parsed by demsm: */
>> + printk("IO:region %s 00000000 00020000\n", gpu->name);
>> + for (i = 0; i < ARRAY_SIZE(a3xx_registers); i += 2) {
>> + uint32_t start = a3xx_registers[i];
>> + uint32_t end = a3xx_registers[i+1];
>> + uint32_t addr;
>> +
>> + for (addr = start; addr <= end; addr++) {
>> + uint32_t val = gpu_read(gpu, addr);
>> + printk("IO:R %08x %08x\n", addr<<2, val);
>> + }
>> + }
>> +}
>> +
>> static const struct adreno_gpu_funcs funcs = {
>> .base = {
>> .get_param = adreno_get_param,
>> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
>> b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
>> index d321099..cf6eb97 100644
>> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
>> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
>> @@ -260,6 +260,24 @@ void adreno_show(struct msm_gpu *gpu, struct seq_file
>> *m)
>> }
>> #endif
>>
>> +/* would be nice to not have to duplicate the _show() stuff with
>> printk(): */
>> +void adreno_dump(struct msm_gpu *gpu)
>> +{
>> + struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
>> +
>> + printk("revision: %d (%d.%d.%d.%d)\n",
>> + adreno_gpu->info->revn, adreno_gpu->rev.core,
>> + adreno_gpu->rev.major, adreno_gpu->rev.minor,
>> + adreno_gpu->rev.patchid);
>> +
>> + printk("fence: %d/%d\n", adreno_gpu->memptrs->fence,
>> + gpu->submitted_fence);
>> + printk("rptr: %d\n", adreno_gpu->memptrs->rptr);
>> + printk("wptr: %d\n", adreno_gpu->memptrs->wptr);
>> + printk("rb wptr: %d\n", get_wptr(gpu->rb));
>> +
>> +}
>> +
>
>
> We should introduce you to the gooey wonderfulness of the snapshot :) All
> in
> due time.
if I get the rd dumping upstream (for which I first need to fix some
chicken/egg problem in drm debugfs init), that plus scratch register
writes (for tile and draw # so I can "triangulate" the position), it's
actually not a bad way to debug.
(although I suppose there are some juicy status bits in the register
dump which would be pretty helpful too if I knew what they meant :-P)
BR,
-R
> Jordan
> --
> The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> hosted by The Linux Foundation
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