[Mesa-dev] [PATCH] i965: Fix calculation of layers array length for isl_view

[Danylo Piliaiev]

On 9/7/18 5:48 PM, Ilia Mirkin wrote:
> On Fri, Sep 7, 2018 at 10:41 AM, Danylo Piliaiev
> <danylo.piliaiev at gmail.com> wrote:
>> Comment for array_len field states:
>>   "Indicates the number of array elements starting at
>>     Base Array Layer."
>>
>> And most usages of array_len expect it to be equal or less than
>>   total layers - base layer
>>
>> Fixes: 5a8c8903
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107856
>>
>> Signed-off-by: Danylo Piliaiev <danylo.piliaiev at globallogic.com>
>> ---
>>   src/mesa/drivers/dri/i965/brw_wm_surface_state.c | 6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
>> index 42af41aca3..6adf4a5836 100644
>> --- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
>> +++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
>> @@ -1539,6 +1539,8 @@ update_image_surface(struct brw_context *brw,
>>         } else {
>>            struct intel_texture_object *intel_obj = intel_texture_object(obj);
>>            struct intel_mipmap_tree *mt = intel_obj->mt;
>> +
>> +         const unsigned base_layer = obj->MinLayer + u->_Layer;
>>            const unsigned num_layers = u->Layered ?
>>               get_image_num_layers(mt, obj->Target, u->Level) : 1;
>>
>> @@ -1546,8 +1548,8 @@ update_image_surface(struct brw_context *brw,
>>               .format = format,
>>               .base_level = obj->MinLevel + u->Level,
>>               .levels = 1,
>> -            .base_array_layer = obj->MinLayer + u->_Layer,
>> -            .array_len = num_layers,
>> +            .base_array_layer = base_layer,
>> +            .array_len = num_layers - base_layer,
> See above - num_layers can be 1 if the image isn't bound as a layered
> image. But base layer can be whatever -- so this will end up as
> negative. I think the adjustment needs to be done only for the
> u->Layered case.

Oh, I see it now, thanks! Unless Lionel's patch for this issue is better 
I'll send v2 of my patch.