Re: [PATCH 1/3] drm/i915: add function for GT related workarounds

Chris Wilson
2016-01-25T17:10:28Z

On Mon, Jan 25, 2016 at 04:41:42PM +0000, Arun Siluvery wrote:
> On 25/01/2016 16:17, Chris Wilson wrote:
> >On Mon, Jan 25, 2016 at 02:43:06PM +0000, Gore, Tim wrote:
> >>
> >>
> >>Tim Gore
> >>Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ
> >>
> >>
> >>>-----Original Message-----
> >>>From: Mika Kuoppala [mailto:mika.kuoppala@linux.intel.com]
> >>>Sent: Monday, January 25, 2016 2:39 PM
> >>>To: Gore, Tim; intel-gfx@lists.freedesktop.org
> >>>Cc: Gore, Tim; arun.siluvery@linux.intel.com
> >>>Subject: Re: [PATCH 1/3] drm/i915: add function for GT related workarounds
> >>>
> >>>tim.gore@intel.com writes:
> >>>
> >>>>From: Tim Gore <tim.gore@intel.com>
> >>>>
> >>>>Add a function that is a place for workarounds that are GT related but
> >>>>not required per ring. This function is called on driver load and also
> >>>>after a reset and on resume, so it is safe for workarounds that get
> >>>>clobbered in these situations.
> >>>>
> >>>>Signed-off-by: Tim Gore <tim.gore@intel.com>
> >>>>---
> >>>> drivers/gpu/drm/i915/i915_gem_gtt.c | 12 ++++++++++++
> >>>> 1 file changed, 12 insertions(+)
> >>>>
> >>>>diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c
> >>>>b/drivers/gpu/drm/i915/i915_gem_gtt.c
> >>>>index 7377b67..fe960d5 100644
> >>>>--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> >>>>+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> >>>>@@ -2132,6 +2132,16 @@ static void i915_address_space_init(struct
> >>>i915_address_space *vm,
> >>>> list_add_tail(&vm->global_link, &dev_priv->vm_list); }
> >>>>
> >>>>+void gtt_write_workarounds(struct drm_device *dev) {
> >>>
> >>>static void
> >>>
> >>>This can be squashed with 2/3.
> >>>
> >>>-Mika
> >>>
> >>Do you mean all squashed together, into a single patch?
> >
> >I would. They are all setting the same register to a nominal value, for
> >the same purpose.
>
> Don't we normally split WA into individual patches or is this only
> for this WA?

Is it not the same w/a applied to different generations? You either
split it per device, so that a bisect + revert only affects one machine,
or not all. Choose your poison.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre