From: "H. Nikolaus Schaller" <hns@goldelico.com>
To: Andreas Kemnade <andreas@kemnade.info>
Cc: Bin Liu <b-liu@ti.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Linux USB Mailing List <linux-usb@vger.kernel.org>,
linux-omap <linux-omap@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Tony Lindgren <tony@atomide.com>,
Discussions about the Letux Kernel
<letux-kernel@openphoenux.org>
Subject: Re: [Letux-kernel] [PATCH v2] musb: omap2430: do not assume balanced enable()/disable()
Date: Wed, 3 Aug 2016 19:07:09 +0200 [thread overview]
Message-ID: <FFDA9A63-599B-44CA-B244-C8860D9E01D9@goldelico.com> (raw)
In-Reply-To: <1470238731-32358-1-git-send-email-andreas@kemnade.info>
> Am 03.08.2016 um 17:38 schrieb Andreas Kemnade <andreas@kemnade.info>:
>
> The code assumes that omap2430_musb_enable() and
> omap2430_musb_disable() are called in a balanced way.
> That fact is broken by the fact that musb_init_controller() calls
> musb_platform_disable() to switch from unknown state to off state
> on initialisation.
>
> 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().
> So when usb gadget is started the phy is not powered on.
> Depending on the phy used that caused various problems.
> Besides of causing usb problems, that can also have side effects.
>
> In the case of using the phy_twl4030, that prevents also charging
> the battery via usb (using twl4030_charger) and so makes further
> kernel debugging hard.
> The problem was seen with 4.7 on an openphoenux gta04. It has a DM3730
> SoC and a TPS65950 companion. phy->power never became 1
s/TPS65950/TPS65950 (twl4030)/
> and so the usb did get powered on.
s/did get/did not get/
maybe add:
All this prevents detection of cable plugin-events and VBUS measurement
and setting OTG_EN before charging is attempted.
>
> The patch prevents phy_power_off() from being called when
> it is already off.
>
> Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> ---
> changes in v2:
> improved commit message
>
> drivers/usb/musb/omap2430.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/musb/omap2430.c b/drivers/usb/musb/omap2430.c
> index 0b4cec9..c1a2b7b 100644
> --- a/drivers/usb/musb/omap2430.c
> +++ b/drivers/usb/musb/omap2430.c
> @@ -413,9 +413,10 @@ static void omap2430_musb_disable(struct musb *musb)
> struct device *dev = musb->controller;
> struct omap2430_glue *glue = dev_get_drvdata(dev->parent);
>
> - if (!WARN_ON(!musb->phy))
> - phy_power_off(musb->phy);
> -
> + if (glue->enabled) {
> + if (!WARN_ON(!musb->phy))
> + phy_power_off(musb->phy);
> + }
> if (glue->status != MUSB_UNKNOWN)
> omap_control_usb_set_mode(glue->control_otghs,
> USB_MODE_DISCONNECT);
> --
> 2.1.4
>
> _______________________________________________
> http://projects.goldelico.com/p/gta04-kernel/
> Letux-kernel mailing list
> Letux-kernel@openphoenux.org
> http://lists.goldelico.com/mailman/listinfo.cgi/letux-kernel
next prev parent reply other threads:[~2016-08-03 17:07 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-03 15:38 [PATCH v2] musb: omap2430: do not assume balanced enable()/disable() Andreas Kemnade
2016-08-03 17:07 ` H. Nikolaus Schaller [this message]
2016-08-04 14:29 ` [Letux-kernel] " Tony Lindgren
2016-08-04 14:49 ` H. Nikolaus Schaller
2016-08-04 15:01 ` Tony Lindgren
2016-08-04 20:59 ` Andreas Kemnade
2016-08-04 16:31 ` Andreas Kemnade
2016-08-04 16:44 ` Andreas Kemnade
2016-08-05 13:55 ` Tony Lindgren
2016-08-05 15:20 ` Andreas Kemnade
2016-08-06 6:21 ` Tony Lindgren
2016-08-09 5:35 ` Andreas Kemnade
2016-08-11 18:25 ` Tony Lindgren
2016-09-09 19:27 ` [v2] " Laurent Pinchart
2016-09-09 20:08 ` Tony Lindgren
2016-09-09 20:21 ` Laurent Pinchart
2016-09-09 20:40 ` Andreas Kemnade
2016-09-09 20:55 ` Tony Lindgren
2016-09-09 20:51 ` Tony Lindgren
2016-09-09 21:22 ` Andreas Kemnade
2016-09-09 21:33 ` Tony Lindgren
2016-09-09 23:40 ` Tony Lindgren
2016-09-10 11:27 ` Andreas Kemnade
2016-09-10 13:07 ` Tony Lindgren
2016-09-11 9:06 ` Laurent Pinchart
2016-09-12 14:35 ` Tony Lindgren
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=FFDA9A63-599B-44CA-B244-C8860D9E01D9@goldelico.com \
--to=hns@goldelico.com \
--cc=andreas@kemnade.info \
--cc=b-liu@ti.com \
--cc=gregkh@linuxfoundation.org \
--cc=letux-kernel@openphoenux.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=tony@atomide.com \
/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;
as well as URLs for NNTP newsgroup(s).