public inbox for intel-gfx@lists.freedesktop.org
 help / color / mirror / Atom feed
From: Mahesh Kumar <mahesh1.kumar@intel.com>
To: Chris Wilson <chris@chris-wilson.co.uk>, intel-gfx@lists.freedesktop.org
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Subject: Re: [PATCH] drm/i915/: Initialise trans_min for skl_compute_transition_wm()
Date: Wed, 8 Nov 2017 10:39:59 +0530	[thread overview]
Message-ID: <b71e4746-1c9e-0ff7-c4f6-e3ccfef47cd2@intel.com> (raw)
In-Reply-To: <20171107182704.18453-1-chris@chris-wilson.co.uk>

Hi,


On Tuesday 07 November 2017 11:57 PM, Chris Wilson wrote:
> clang spots
>
> drivers/gpu/drm/i915/intel_pm.c:4655:6: warning: variable 'trans_min' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
>          if (INTEL_GEN(dev_priv) >= 10)
>
> but fortunately for us we skip the function unless on a gen10+ device.
> However, to keep the function generic in case we do want to re-enable it
> for gen9 again, initialise trans_min to 0.
>
> References: ca47667f523e ("drm/i915/gen10: Calculate and enable transition WM")
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Mahesh Kumar <mahesh1.kumar@intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Jani Nikula <jani.nikula@linux.intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
>   drivers/gpu/drm/i915/intel_pm.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index b75c4cf074ff..40da5001be28 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -4652,6 +4652,7 @@ static void skl_compute_transition_wm(struct intel_crtc_state *cstate,
>   	if (!dev_priv->ipc_enabled)
>   		goto exit;
>   
> +	trans_min = 0;
>   	if (INTEL_GEN(dev_priv) >= 10)
>   		trans_min = 4;
BSpec WA section tells not to enable transition watermark for any GEN-9 
platforms (that was the assumption with this patch)
But anyway trans_min value for GEN9 is 14 blocks, IMO adding else case 
with trans_min = 14; will be logical solution to this.

-Mahesh
>   

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

  parent reply	other threads:[~2017-11-08  5:06 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-11-07 18:27 [PATCH] drm/i915/: Initialise trans_min for skl_compute_transition_wm() Chris Wilson
2017-11-07 18:45 ` ✗ Fi.CI.BAT: warning for " Patchwork
2017-11-08  5:09 ` Mahesh Kumar [this message]
2017-11-08 20:00   ` [PATCH] " Ville Syrjälä
2017-11-09  3:49     ` Mahesh Kumar
2017-11-09 14:16       ` Mahesh Kumar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=b71e4746-1c9e-0ff7-c4f6-e3ccfef47cd2@intel.com \
    --to=mahesh1.kumar@intel.com \
    --cc=chris@chris-wilson.co.uk \
    --cc=intel-gfx@lists.freedesktop.org \
    --cc=rodrigo.vivi@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox