Re: [PATCH 07/14] drm/i915: Add bigjoiner and uncompressed joiner hw readout sanity checks

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 9/6/2024 9:09 PM, Ville Syrjälä wrote:
> On Fri, Sep 06, 2024 at 06:28:00PM +0530, Ankit Nautiyal wrote:
>> From: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
>>
>> Adding sanity checks for primary and secondary bigjoiner/uncompressed
>> bitmasks, should make it easier to spot possible issues.
>>
>> Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
>> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_display.c | 24 ++++++++++++++++++++
>>   1 file changed, 24 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
>> index cdc7531311fc..6f098383479f 100644
>> --- a/drivers/gpu/drm/i915/display/intel_display.c
>> +++ b/drivers/gpu/drm/i915/display/intel_display.c
>> @@ -3638,11 +3638,17 @@ static void enabled_bigjoiner_pipes(struct drm_i915_private *dev_priv,
>>   	}
>>   }
>>   
>> +static u8 expected_secondary_pipes(u8 primary_pipes)
>> +{
>> +	return primary_pipes << 1;
>> +}
> Extracting this should be a separate patch really since it
> was already in the code until the previous patch erroneously
> removed it.

Sure, will move this to another patch.


>
>> +
>>   static void enabled_joiner_pipes(struct drm_i915_private *dev_priv,
>>   				 u8 *primary_pipes, u8 *secondary_pipes)
>>   {
>>   	u8 primary_uncompressed_joiner_pipes, primary_bigjoiner_pipes;
>>   	u8 secondary_uncompressed_joiner_pipes, secondary_bigjoiner_pipes;
>> +	u8 uncompressed_joiner_pipes, bigjoiner_pipes;
>>   
>>   	enabled_uncompressed_joiner_pipes(dev_priv, &primary_uncompressed_joiner_pipes,
>>   					  &secondary_uncompressed_joiner_pipes);
>> @@ -3650,6 +3656,24 @@ static void enabled_joiner_pipes(struct drm_i915_private *dev_priv,
>>   	enabled_bigjoiner_pipes(dev_priv, &primary_bigjoiner_pipes,
>>   				&secondary_bigjoiner_pipes);
>>   
>> +	uncompressed_joiner_pipes = primary_uncompressed_joiner_pipes |
>> +				    secondary_uncompressed_joiner_pipes;
>> +	bigjoiner_pipes = primary_bigjoiner_pipes | secondary_bigjoiner_pipes;
>> +
>> +	drm_WARN(&dev_priv->drm, (uncompressed_joiner_pipes & bigjoiner_pipes) != 0,
>> +		 "Uncomressed joiner pipes(%x) and bigjoiner pipes(%x) can't intersect\n",
>> +		 uncompressed_joiner_pipes, bigjoiner_pipes);
> Please use 0x%x for printing hex numbers
>
> Side note: maybe we should switch to the standard %#x instead?
> Though we'd need to double check whether prink() follows the
> idiotic C standard or not:
>   printf("%#x", 1) -> 0x1, for any non-zero value
>   bs.
>   printf("%#x", 0) -> 0 (sigh)
>
> If printk() behaves the same way then I want to see %#x anywhere
> (pretty sure we do use it in a few places already though).

I will check how %#x behaves with 0 with printk, accordingly will use 
0x%x or %x#x, (we do use it in some places).

Regards,

Ankit

>
>
>> +	drm_WARN(&dev_priv->drm, secondary_bigjoiner_pipes !=
>> +		 expected_secondary_pipes(primary_bigjoiner_pipes),
>> +		 "Wrong secondary bigjoiner pipes(expected %x, current %x)\n",
>> +		 expected_secondary_pipes(primary_bigjoiner_pipes),
>> +		 secondary_bigjoiner_pipes);
>> +	drm_WARN(&dev_priv->drm, secondary_uncompressed_joiner_pipes !=
>> +		 expected_secondary_pipes(primary_uncompressed_joiner_pipes),
>> +		 "Wrong secondary uncompressed joiner pipes(expected %x, current %x)\n",
>> +		 expected_secondary_pipes(primary_uncompressed_joiner_pipes),
>> +		 secondary_uncompressed_joiner_pipes);
>> +
>>   	*primary_pipes = 0;
>>   	*secondary_pipes = 0;
>>   
>> -- 
>> 2.45.2