From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>,
devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, linux-mmc@vger.kernel.org,
linux-pm@vger.kernel.org, linux-usb@vger.kernel.org,
Ulf Hansson <ulf.hansson@linaro.org>,
Sebastian Reichel <sre@kernel.org>,
Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>,
David Woodhouse <dwmw2@infradead.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Mark Brown <broonie@kernel.org>,
tjakobi@math.uni-bielefeld.de, m.szyprowski@samsung.com,
hverkuil@xs4all.nl,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: Re: [RFC v2 10/13] usb: hub: Power sequence the ports on activation
Date: Thu, 5 May 2016 19:37:03 +0200 [thread overview]
Message-ID: <20160505173703.GA3034@kozik-lap> (raw)
In-Reply-To: <Pine.LNX.4.44L0.1605051007040.2008-100000@iolanthe.rowland.org>
On Thu, May 05, 2016 at 10:09:47AM -0400, Alan Stern wrote:
> On Thu, 5 May 2016, Krzysztof Kozlowski wrote:
>
> > The autodetection of attached USB device might not work on certain
> > boards where the power is delivered externally. These devices also might
> > require a hard reset. Use pwrseq for that in USB hub.
> >
> > Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> > ---
> > drivers/usb/core/hub.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> > index 1c82fcc448f5..0fddaacc62bf 100644
> > --- a/drivers/usb/core/hub.c
> > +++ b/drivers/usb/core/hub.c
> > @@ -26,6 +26,7 @@
> > #include <linux/mutex.h>
> > #include <linux/random.h>
> > #include <linux/pm_qos.h>
> > +#include <linux/pwrseq.h>
> >
> > #include <asm/uaccess.h>
> > #include <asm/byteorder.h>
> > @@ -1661,7 +1662,17 @@ static int hub_configure(struct usb_hub *hub,
> >
> > usb_hub_adjust_deviceremovable(hdev, hub->descriptor);
> >
> > + /* FIXME: When do the pre-power-on? */
>
> It's hard to answer this without knowing what pre-power-on involves.
In my particular case, I want to achieve a full reset through regulator (off
and on) because the bootloader left it in initialized state. I assume
that if bootloader did not configure the device, the reset won't be
harmful.
In a MMC case, this pre-power-on on is setting the 'reset' GPIO (thus
triggering the reset) and post-power-on is clearing the 'reset'.
> Why not create a pwrseq_power_on() routine that does pre_power_on
> followed by post_power_on?
For my purpose it seems sensible.
>
> > + /*
> > + for (i = 0; i < maxchild; i++)
> > + pwrseq_pre_power_on(hub->ports[i]->pwrseq);
> > + */
> > +
> > + for (i = 0; i < maxchild; i++)
> > + pwrseq_post_power_on(hub->ports[i]->pwrseq);
>
> This is patch 10/13. hub->ports[i]->pwrseq doesn't get added until
> 11/13. Obviously you never tried compiling each patch in the series.
Ahh yes, I forgot to reorder them. Thanks for spotting this.
>
> > +
> > hub_activate(hub, HUB_INIT);
> > +
>
> Unnecessary blank line added.
Thanks for feedback,
Krzysztof
next prev parent reply other threads:[~2016-05-05 17:37 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-05 12:34 [RFC v2 00/13] usb/mmc/power: Fix USB/LAN when TFTP booting Krzysztof Kozlowski
2016-05-05 12:34 ` [RFC v2 01/13] usb: misc: usb3503: Clean up on driver unbind Krzysztof Kozlowski
2016-05-05 18:32 ` Javier Martinez Canillas
2016-05-06 6:13 ` Krzysztof Kozlowski
2016-05-05 12:34 ` [RFC v2 02/13] power/mmc: Move pwrseq drivers to power/pwrseq Krzysztof Kozlowski
2016-05-05 18:44 ` Javier Martinez Canillas
2016-05-06 6:15 ` Krzysztof Kozlowski
2016-05-05 12:34 ` [RFC v2 03/13] MAINTAINERS: Retain Ulf Hansson as the same maintainer of pwrseq Krzysztof Kozlowski
2016-05-05 18:46 ` Javier Martinez Canillas
2016-05-05 12:34 ` [RFC v2 06/13] power: pwrseq: Generalize mmc_pwrseq operations by removing mmc prefix Krzysztof Kozlowski
[not found] ` <1462451666-17945-7-git-send-email-k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-05-05 19:14 ` Javier Martinez Canillas
2016-05-05 12:34 ` [RFC v2 07/13] power: pwrseq: simple: Add support for toggling regulator Krzysztof Kozlowski
2016-05-05 19:31 ` Javier Martinez Canillas
2016-05-06 6:24 ` Krzysztof Kozlowski
2016-05-05 12:34 ` [RFC v2 08/13] usb: hub: Handle deferred probe Krzysztof Kozlowski
2016-05-05 19:33 ` Javier Martinez Canillas
2016-05-05 12:34 ` [RFC v2 09/13] power: pwrseq: Add support for USB hubs with external power Krzysztof Kozlowski
[not found] ` <1462451666-17945-10-git-send-email-k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-05-05 19:52 ` Javier Martinez Canillas
2016-05-06 6:26 ` Krzysztof Kozlowski
2016-05-05 12:34 ` [RFC v2 10/13] usb: hub: Power sequence the ports on activation Krzysztof Kozlowski
[not found] ` <1462451666-17945-11-git-send-email-k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-05-05 14:09 ` Alan Stern
2016-05-05 17:37 ` Krzysztof Kozlowski [this message]
2016-05-05 19:56 ` Javier Martinez Canillas
[not found] ` <1462451666-17945-1-git-send-email-k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-05-05 12:34 ` [RFC v2 04/13] power: pwrseq: Enable COMPILE_TEST for drivers Krzysztof Kozlowski
[not found] ` <1462451666-17945-5-git-send-email-k.kozlowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-05-05 18:57 ` Javier Martinez Canillas
2016-05-05 12:34 ` [RFC v2 05/13] power: pwrseq: Remove mmc prefix from mmc_pwrseq Krzysztof Kozlowski
2016-05-05 19:09 ` Javier Martinez Canillas
2016-05-06 6:20 ` Krzysztof Kozlowski
2016-05-05 12:34 ` [RFC v2 11/13] usb: port: Parse pwrseq phandle from Device Tree Krzysztof Kozlowski
2016-05-05 20:10 ` Javier Martinez Canillas
2016-05-06 6:27 ` Krzysztof Kozlowski
2016-05-05 12:34 ` [RFC v2 12/13] ARM: dts: exynos: Switch the buck8 to GPIO mode on Odroid U3 Krzysztof Kozlowski
2016-05-05 20:11 ` Javier Martinez Canillas
2016-05-05 22:42 ` [RFC v2 00/13] usb/mmc/power: Fix USB/LAN when TFTP booting Rob Herring
2016-05-06 5:44 ` Peter Chen
2016-05-06 6:12 ` Krzysztof Kozlowski
[not found] ` <572C35C8.9080709-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
2016-05-06 7:15 ` Peter Chen
2016-05-06 6:10 ` Krzysztof Kozlowski
2016-05-06 13:01 ` Rob Herring
2016-05-09 7:46 ` Ulf Hansson
2016-05-09 18:18 ` Rob Herring
2016-05-10 11:02 ` Ulf Hansson
[not found] ` <CAPDyKFq2=mqujFjvJSYxg2nVmK=OrBKLtFfb-ErNJO3Zr_LMVw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2016-05-28 3:36 ` Peter Chen
2016-05-31 0:58 ` Peter Chen
2016-05-31 11:54 ` Krzysztof Kozlowski
2016-05-05 12:34 ` [RFC v2 13/13] ARM: dts: exynos: Fix LAN and HUB after bootloader initialization on Odroid U3 Krzysztof Kozlowski
2016-05-05 20:16 ` Javier Martinez Canillas
2016-05-06 6:28 ` Krzysztof Kozlowski
2016-12-13 12:20 ` [RFC v2 00/13] usb/mmc/power: Fix USB/LAN when TFTP booting Hans Verkuil
2016-12-13 12:34 ` Hans Verkuil
2016-12-13 13:53 ` Krzysztof Kozlowski
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=20160505173703.GA3034@kozik-lap \
--to=k.kozlowski@samsung.com \
--cc=b.zolnierkie@samsung.com \
--cc=broonie@kernel.org \
--cc=dbaryshkov@gmail.com \
--cc=devicetree@vger.kernel.org \
--cc=dwmw2@infradead.org \
--cc=gregkh@linuxfoundation.org \
--cc=hverkuil@xs4all.nl \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mmc@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=linux-samsung-soc@vger.kernel.org \
--cc=linux-usb@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=sre@kernel.org \
--cc=stern@rowland.harvard.edu \
--cc=tjakobi@math.uni-bielefeld.de \
--cc=ulf.hansson@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).