From: Peter Chen <hzpeterchen@gmail.com>
To: Stephen Boyd <stephen.boyd@linaro.org>
Cc: linux-usb@vger.kernel.org, Felipe Balbi <balbi@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Neil Armstrong <narmstrong@baylibre.com>,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
Bjorn Andersson <bjorn.andersson@linaro.org>,
devicetree@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
Peter Chen <peter.chen@nxp.com>,
Andy Gross <andy.gross@linaro.org>,
Kishon Vijay Abraham I <kishon@ti.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v5 23/23] phy: Add support for Qualcomm's USB HS phy
Date: Mon, 24 Oct 2016 10:14:12 +0800 [thread overview]
Message-ID: <20161024021412.GA9840@b29397-desktop> (raw)
In-Reply-To: <147707842313.25848.12479294741874867656@sboyd-linaro>
On Fri, Oct 21, 2016 at 12:33:43PM -0700, Stephen Boyd wrote:
> Quoting Peter Chen (2016-10-20 19:20:30)
> > On Thu, Oct 20, 2016 at 04:20:38PM -0700, Stephen Boyd wrote:
> > > Quoting Stephen Boyd (2016-10-17 18:56:36)
> > > > +
> > > > +static int
> > > > +qcom_usb_hs_phy_vbus_notifier(struct notifier_block *nb, unsigned long event,
> > > > + void *ptr)
> > > > +{
> > > > + struct qcom_usb_hs_phy *uphy;
> > > > + int is_host;
> > > > + u8 addr;
> > > > +
> > > > + uphy = container_of(nb, struct qcom_usb_hs_phy, vbus_notify);
> > > > + is_host = extcon_get_cable_state_(uphy->id_edev, EXTCON_USB_HOST);
> > >
> > > Please don't apply this patch. This call now deadlocks on v4.9-rc1
> > > because of how extcon_get_cable_state_() now grabs a lock that is
> > > already held here when we're inside the notifier. It's not really
> > > required that we grab the lock in extcon there, but this has exposed a
> > > flaw in the logic anyway. We don't know if the id pin is going to toggle
> > > before or after this function is called, so we should really keep track
> > > of both vbus and id state in this driver and then do the same ulpi
> > > writes from two different notifiers for both vbus and id pin. We would
> > > be duplicating work sometimes, but that's pretty much the best solution
> > > I can come up with. Otherwise it's racy.
> > >
> >
> > Why you need to care id status? If EXTCON_USB event has happened, and
> > event is true, you can set, otherwise, it is clear operation, that's
> > to say you may not need have id extcon phandle, do you think so?
> >
>
> I need to add a comment to the code here because I forgot what was going
> on.
>
> Either way, this code is pulling D+ up when we're in device mode. We
> don't want to do the pullup if we're a host, and vbus extcon only tells
> us if the cable is attached so we can't just rely on that one bit of
> information.
>
> I suppose that's not really appropriate to do via extcon though in the
> phy driver though, so I'm thinking that it should be rewritten to use
> the phy_set_mode() feature of the phy framework. Basically,
> ci_udc_pullup() will call phy_set_mode() with PHY_MODE_USB_DEVICE or
> PHY_MODE_USB_HOST and then we can set or clear these bits in the ulpi
> register space. I think that will make things simpler here and things
> like soft-connect will work better. Sound good?
I agree with you, and you may notify controller role through
phy_set_mode at the controller probe and role switch routine.
--
Best Regards,
Peter Chen
next prev parent reply other threads:[~2016-10-24 2:14 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-18 1:56 [PATCH v5 00/23] Support qcom's HSIC USB and rewrite USB2 HS support Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 03/23] usb: ulpi: Support device discovery via DT Stephen Boyd
2016-10-18 16:44 ` Rob Herring
2016-11-11 11:02 ` Heikki Krogerus
2016-10-18 1:56 ` [PATCH v5 04/23] usb: chipidea: Only read/write OTGSC from one place Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 05/23] usb: chipidea: Handle extcon events properly Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 06/23] usb: chipidea: Add platform flag for wrapper phy management Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 07/23] usb: chipidea: Notify events when switching host mode Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 08/23] usb: chipidea: Remove locking in ci_udc_start() Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 09/23] usb: chipidea: Add support for ULPI PHY bus Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 10/23] usb: chipidea: Consolidate extcon notifiers Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 11/23] usb: chipidea: Emulate OTGSC interrupt enable path Stephen Boyd
2016-10-19 1:15 ` Peter Chen
2016-10-19 1:53 ` Stephen Boyd
2016-10-19 8:02 ` Peter Chen
2016-10-20 6:55 ` Stephen Boyd
2016-10-20 10:10 ` Peter Chen
2016-10-20 20:36 ` Stephen Boyd
2016-10-21 2:14 ` Peter Chen
2016-10-21 17:57 ` Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 12/23] usb: chipidea: msm: Mark device as runtime pm active Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 13/23] usb: chipidea: msm: Rely on core to override AHBBURST Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 14/23] usb: chipidea: msm: Use hw_write_id_reg() instead of writel Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 15/23] usb: chipidea: msm: Add proper clk and reset support Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 16/23] usb: chipidea: msm: Mux over secondary phy at the right time Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 17/23] usb: chipidea: msm: Restore wrapper settings after reset Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 18/23] usb: chipidea: msm: Make platform data driver local instead of global Stephen Boyd
[not found] ` <20161018015636.11701-1-stephen.boyd-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2016-10-18 1:56 ` [PATCH v5 01/23] of: device: Support loading a module with OF based modalias Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 02/23] of: device: Export of_device_{get_modalias,uvent_modalias} to modules Stephen Boyd
[not found] ` <20161018015636.11701-3-stephen.boyd-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2016-10-18 5:20 ` [PATCH v5 02/23] of: device: Export of_device_{get_modalias, uvent_modalias} " Chen-Yu Tsai
2016-10-24 12:19 ` Chen-Yu Tsai
2016-10-24 19:48 ` Stephen Boyd
2016-10-25 1:16 ` Peter Chen
2016-11-04 20:51 ` Stephen Boyd
2016-11-07 1:29 ` Peter Chen
2016-11-07 1:56 ` Chen-Yu Tsai
[not found] ` <CAGb2v66C15fU1b2+xNDV8Fv2kmmKXyUknA8=9wXztUcs8CNKLg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-11-10 21:42 ` Rob Herring
2016-11-11 3:01 ` Chen-Yu Tsai
2016-11-11 4:25 ` Javier Martinez Canillas
2016-10-18 1:56 ` [PATCH v5 19/23] usb: chipidea: msm: Add reset controller for PHY POR bit Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 20/23] usb: chipidea: msm: Handle phy power states Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 23/23] phy: Add support for Qualcomm's USB HS phy Stephen Boyd
2016-10-18 16:46 ` Rob Herring
2016-10-18 16:47 ` Rob Herring
[not found] ` <20161018015636.11701-24-stephen.boyd-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
2016-10-20 23:20 ` Stephen Boyd
2016-10-21 2:20 ` Peter Chen
2016-10-21 19:33 ` Stephen Boyd
2016-10-24 2:14 ` Peter Chen [this message]
2016-10-18 9:31 ` [PATCH v5 00/23] Support qcom's HSIC USB and rewrite USB2 HS support Peter Chen
2016-10-18 20:51 ` Stephen Boyd
2016-11-11 7:40 ` Peter Chen
2016-11-14 19:35 ` Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 21/23] usb: chipidea: msm: Be silent on probe defer errors Stephen Boyd
2016-10-18 1:56 ` [PATCH v5 22/23] phy: Add support for Qualcomm's USB HSIC phy Stephen Boyd
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=20161024021412.GA9840@b29397-desktop \
--to=hzpeterchen@gmail.com \
--cc=andy.gross@linaro.org \
--cc=arnd@arndb.de \
--cc=balbi@kernel.org \
--cc=bjorn.andersson@linaro.org \
--cc=devicetree@vger.kernel.org \
--cc=kishon@ti.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=narmstrong@baylibre.com \
--cc=peter.chen@nxp.com \
--cc=robh+dt@kernel.org \
--cc=stephen.boyd@linaro.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;
as well as URLs for NNTP newsgroup(s).