[Intel-gfx] [PATCH] drm/i915/gtt: Correct unshifted 'from' for gen8_ppgtt_alloc errors

[Michal Wajdeczko]

On Fri, 19 Jul 2019 15:15:24 +0200, Chris Wilson  
<chris at chris-wilson.co.uk> wrote:

> Since the underlying __gen8_ppgtt_clear takes the shifted address, we
> must remember to provide it with the preshifted original start address.
>
> Reported-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c  
> b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 220aba5a94d2..031bcd22f5e6 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -1103,7 +1103,7 @@ static int __gen8_ppgtt_alloc(struct  
> i915_address_space * const vm,
>  static int gen8_ppgtt_alloc(struct i915_address_space *vm,
>  			    u64 start, u64 length)
>  {
> -	u64 from = start;
> +	u64 from;
>  	int err;
> 	GEM_BUG_ON(!IS_ALIGNED(start, BIT_ULL(GEN8_PTE_SHIFT)));
> @@ -1112,6 +1112,7 @@ static int gen8_ppgtt_alloc(struct  
> i915_address_space *vm,
>  	start >>= GEN8_PTE_SHIFT;
>  	length >>= GEN8_PTE_SHIFT;
>  	GEM_BUG_ON(length == 0);
> +	from = start;
> 	err = __gen8_ppgtt_alloc(vm, i915_vm_to_ppgtt(vm)->pd,
>  				 &start, start + length, vm->top);

Tested-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko at intel.com>

there is still one issue with __gen8_ppgtt_clear called
 from here but this will be covered in upcoming patch

Michal