linux-kernel - [38/49] usb: musb: fix pm

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20120110215604.850635953@clark.kroah.org>
Date:	Tue, 10 Jan 2012 13:55:41 -0800
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk, Hema HK <hemahk@...com>,
	Felipe Contreras <felipe.contreras@...il.com>,
	Felipe Balbi <balbi@...com>
Subject: [38/49] usb: musb: fix pm_runtime mismatch

3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Felipe Contreras <felipe.contreras@...il.com>

commit 772aed45b604c5ff171f0f12c12392d868333f79 upstream.

In musb_init_controller() there's a pm_runtime_put(), but there's no
pm_runtime_get(), which creates a mismatch that causes the driver to
sleep when it shouldn't.

This was introduced in 7acc619[1], but it wasn't triggered in my setup
until 18a2689[2] was merged to Linus' branch at point df0914[3]. IOW;
when PM is working as it was supposed to.

However, it seems most of the time this is used in a way that keeps the
counter above 0, so nobody noticed. Also, it seems to depend on the
configuration used in versions before 3.1, but not later (or in it).

I found the problem by loading isp1704_charger before any usb gadgets:
http://article.gmane.org/gmane.linux.kernel/1226122

All versions after 2.6.39 are affected.

[1] usb: musb: Idle path retention and offmode support for OMAP3
[2] OMAP2+: musb: hwmod adaptation for musb registration
[3] Merge branch 'omap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6

Cc: Hema HK <hemahk@...com>
Signed-off-by: Felipe Contreras <felipe.contreras@...il.com>
Signed-off-by: Felipe Balbi <balbi@...com>

---
 drivers/usb/musb/musb_core.c |    2 --
 1 file changed, 2 deletions(-)

--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2012,8 +2012,6 @@ musb_init_controller(struct device *dev,
 	if (status < 0)
 		goto fail3;
 
-	pm_runtime_put(musb->controller);
-
 	status = musb_init_debugfs(musb);
 	if (status < 0)
 		goto fail4;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/