Re: [PATCH] drm/i915: Use true PPGTT in Gen8 if execlists are enabled

From: Michel Thierry <michel.thierry@intel.com>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH] drm/i915: Use true PPGTT in Gen8 if execlists are enabled
Date: Mon, 15 Dec 2014 12:47:14 +0000	[thread overview]
Message-ID: <548ED852.6030108@intel.com> (raw)
In-Reply-To: <20141215101114.GS27182@phenom.ffwll.local>


[-- Attachment #1.1: Type: text/plain, Size: 1534 bytes --]

On 12/15/2014 10:11 AM, Daniel Vetter wrote:
> On Thu, Dec 11, 2014 at 12:07:18PM +0000, Michel Thierry wrote:
>> When execlists submission is enabled, try full ppgtt by default.
>>
>> Note, this patch considers that execlist support has been enabled by
>> default on Gen8.
>>
>> Signed-off-by: Michel Thierry <michel.thierry@intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_gem_gtt.c | 9 ++++++---
>>   1 file changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
>> index 171f6ea..4ed3904 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
>> @@ -40,8 +40,8 @@ static int sanitize_enable_ppgtt(struct drm_device *dev, int enable_ppgtt)
>>   
>>   	has_aliasing_ppgtt = INTEL_INFO(dev)->gen >= 6;
>>   	has_full_ppgtt = INTEL_INFO(dev)->gen >= 7;
>> -	if (IS_GEN8(dev))
>> -		has_full_ppgtt = false; /* XXX why? */
>> +	if (IS_GEN8(dev) && !i915.enable_execlists)
>> +		has_full_ppgtt = false; /* Only enforce with execlists */
> Imo this has outlived it's usefulness - enable_ppgtt is an unsafe
> parameter so everyone setting it themselves gets what they need.
> Afair this was just because of the execlist depency on gen8 for ppgtt.
> -Daniel
Not sure if I'm following you up on this...
The aim was to change the default value to _full_ only when execlists 
are also enable (after Thomas' patch).  In gen8, we don't want to have 
full ppgtt with legacy ring submission.


[-- Attachment #1.2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 5510 bytes --]

[-- Attachment #2: Type: text/plain, Size: 159 bytes --]

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
http://lists.freedesktop.org/mailman/listinfo/intel-gfx