public inbox for intel-gfx@lists.freedesktop.org
 help / color / mirror / Atom feed
From: Egbert Eich <eich@suse.com>
To: Daniel Vetter <daniel@ffwll.ch>
Cc: Egbert Eich <eich@suse.de>, intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 0/5] drm/i915 Avoid long delays when reading EDID on eDP
Date: Tue, 25 Nov 2014 18:20:17 +0100	[thread overview]
Message-ID: <21620.47697.32305.320374@linux-qknr.fritz.box> (raw)
In-Reply-To: daniel@ffwll.ch wrote on Tuesday, 25 November 2014 at 14:13:35 +0100

Daniel Vetter writes:

 > Imo this approach with overwrite all the entry points won't scale since
 > besides i2c and dpcd there will be more sooner or later (oui, dp mst, some
 > debugfs userspace dp aux tools, ...).
 > 
 > I think what we need is the same as in the i2c layer has with the
 > xfer_pre/post functions. To make this as painless as possible we should
 > probably refcount that in the dp helper, protected by aux->hw_mutex. That
 > way normal dp reads could just do the xfer_pre/post around the call to
 > aux->transfer while i2c could do it around the entire i2c transaction.

I agree with your idea of having xfer_pre/post functions. 
I'm not sure though if I understand your idea about reference counters:
are you trying to protect from xfer_pre/post being called at different
levels here? 
With my proposal entire transactions (I2C) are serialized thru the pps_mutex 
lock. This is a side effect that's probably unwanted. Is this what you are
trying to avoid by using ref counters?

Cheers,
	Egbert.

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

  reply	other threads:[~2014-11-25 17:20 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-24 17:16 [PATCH 0/5] drm/i915 Avoid long delays when reading EDID on eDP Egbert Eich
2014-11-24 17:16 ` [PATCH 1/5] drm/i915: Try to avoid pps_{lock, unlock}() on DP ports Egbert Eich
2014-11-24 18:28   ` Jani Nikula
2014-11-24 17:16 ` [PATCH 2/5] drm/DP: Create pointer to generic DPCD access function Egbert Eich
2014-11-24 17:16 ` [PATCH 3/5] drm/DP: Export drm_dp_i2c_xfer() DP helper function Egbert Eich
2014-11-24 17:16 ` [PATCH 4/5] drm/DP: Export drm_dp_dpcd_access() " Egbert Eich
2014-11-24 17:16 ` [PATCH 5/5] drm/i915/eDP: Move pps_lock() and edp_panel_vdd_on() to top Egbert Eich
2014-11-25  9:08 ` [PATCH 0/5] drm/i915 Avoid long delays when reading EDID on eDP Jani Nikula
2014-11-25 13:13 ` Daniel Vetter
2014-11-25 17:20   ` Egbert Eich [this message]
2014-11-26  8:57     ` Daniel Vetter

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=21620.47697.32305.320374@linux-qknr.fritz.box \
    --to=eich@suse.com \
    --cc=daniel@ffwll.ch \
    --cc=eich@suse.de \
    --cc=intel-gfx@lists.freedesktop.org \
    /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