public inbox for linux-omap@vger.kernel.org
 help / color / mirror / Atom feed
From: Kevin Hilman <khilman@ti.com>
To: Felipe Balbi <balbi@ti.com>
Cc: linux-omap@vger.kernel.org, Greg Kroah-Hartman <gregkh@suse.de>,
	"open list:MUSB MULTIPOINT H..." <linux-usb@vger.kernel.org>,
	open list <linux-kernel@vger.kernel.org>
Subject: [PATCH] usb: musb: PM: fix context save/restore in suspend/resume path
Date: Tue, 22 Nov 2011 17:18:24 -0800	[thread overview]
Message-ID: <1322011104-21817-1-git-send-email-khilman@ti.com> (raw)

Currently the driver tries to save context in the suspend path, but
will cause an abort if the device is already runtime suspended.  This
happens, for example, if MUSB loaded/compiled-in, in host mode, but no
USB devices are attached.  MUSB will be runtime suspended, but then
attempting a system suspend will crash due to the context save
being attempted while the device is disabled.

On OMAP, as of v3.1, the driver's ->runtime_suspend() callback will be
called late in the suspend path (by the PM domain layer) if the driver
is not already runtime suspended, ensuring a full shutdown.

Therefore, the context save is not needed in the ->suspend() method
since it will be called in the ->runtime_suspend() method anyways
(similarily for resume.)

NOTE: this leaves the suspend/resume methods basically empty (with
      some FIXMEs and comments, but I'll leave it to the maintainers
      to decide whether to remove them.

Signed-off-by: Kevin Hilman <khilman@ti.com>
---
 drivers/usb/musb/musb_core.c |    6 ------
 1 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 20a2873..a057a5a 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2302,18 +2302,12 @@ static int musb_suspend(struct device *dev)
 		 */
 	}
 
-	musb_save_context(musb);
-
 	spin_unlock_irqrestore(&musb->lock, flags);
 	return 0;
 }
 
 static int musb_resume_noirq(struct device *dev)
 {
-	struct musb	*musb = dev_to_musb(dev);
-
-	musb_restore_context(musb);
-
 	/* for static cmos like DaVinci, register values were preserved
 	 * unless for some reason the whole soc powered down or the USB
 	 * module got reset through the PSC (vs just being disabled).
-- 
1.7.6

             reply	other threads:[~2011-11-23  1:18 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-23  1:18 Kevin Hilman [this message]
2011-11-24  9:25 ` [PATCH] usb: musb: PM: fix context save/restore in suspend/resume path Felipe Balbi
2011-11-24  9:27 ` Felipe Balbi

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=1322011104-21817-1-git-send-email-khilman@ti.com \
    --to=khilman@ti.com \
    --cc=balbi@ti.com \
    --cc=gregkh@suse.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=linux-usb@vger.kernel.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