All of lore.kernel.org
 help / color / mirror / Atom feed
From: Zhi Wang <zhi.a.wang@intel.com>
To: "intel-gfx@lists.freedesktop.org" <intel-gfx@lists.freedesktop.org>
Subject: About the wait_for() macro in intel_drv.h
Date: Wed, 15 Jul 2015 22:07:54 +0800	[thread overview]
Message-ID: <55A6693A.1000704@intel.com> (raw)

Hi Gurus:
    Recently we found that the wait_for() marco in intel_drv.h looks
will cause dead lock. wait_for() macro will try to wait jiffies change
in a condition check loop, but when local cpu interrupt is disabled, it
seems the jiffies will never change under a uni-processor environment.
And in forcewake_get/put path, the local cpu irq will always be disabled
by a spin_lock_irqsave() in genX_read() and some genX_write(), So if the
change of HW register (e.g. forcewake ack) turns slow at this time,
there should be a dead lock here I think?

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

             reply	other threads:[~2015-07-16  5:40 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-15 14:07 Zhi Wang [this message]
2015-07-21 12:46 ` About the wait_for() macro in intel_drv.h Wang, Zhi A

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=55A6693A.1000704@intel.com \
    --to=zhi.a.wang@intel.com \
    --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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.