linux-kernel - Re: [PATCH] musb: omap2430: do not assume balanced enable()/disable()

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Date:	Tue, 2 Aug 2016 03:33:34 -0700
From:	Tony Lindgren <tony@...mide.com>
To:	Andreas Kemnade <andreas@...nade.info>
Cc:	Bin Liu <b-liu@...com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	linux-usb@...r.kernel.org, linux-omap@...r.kernel.org,
	linux-kernel@...r.kernel.org, letux-kernel@...nphoenux.org
Subject: Re: [PATCH] musb: omap2430: do not assume balanced enable()/disable()

* Andreas Kemnade <andreas@...nade.info> [160729 11:14]:
> The code assumes that omap2430_musb_enable() and
> omap2430_musb_disable() is called in a balanced way. The
> That fact is broken by the fact that musb_init_controller() calls
> musb_platform_disable() to switch from unknown state to off state.

OK, some spelling issues with the above paragraph though :)

> That means that phy_power_off() is called first so that
> phy->power_count gets -1 and the phy is not enabled on phy_power_on().
> In the probably common case of using the phy_twl4030, that
> prevents also charging the battery and so makes further
> kernel debugging hard.

Is this with v4.7 kernel? Also, care to describe how you hit this
and on which hardware? Just wondering..

> The patch prevents phy_power_off() from being called when
> it is already off.

OK

Regards,

Tony