Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev

From	Russell King - ARM Linux <linux@armlinux.org.uk>
Newsgroups	linux.kernel
Subject	Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev
Date	2016-09-07 11:40 +0200
Message-ID	<seHuN-6ml-19@gated-at.bofh.it> (permalink)
References	<rsBUK-5fq-11@gated-at.bofh.it> <seoBQ-2y1-43@gated-at.bofh.it> <seFMm-5cY-25@gated-at.bofh.it> <seGS5-5U1-21@gated-at.bofh.it> <seHl7-6jf-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On Wed, Sep 07, 2016 at 05:29:01PM +0800, Peter Chen wrote:
> On Wed, Sep 07, 2016 at 10:52:46AM +0200, Arnd Bergmann wrote:
> > On Wednesday, September 7, 2016 3:44:28 PM CEST Peter Chen wrote:
> > > 
> > > The pre-condition of DT function at USB HCD core works is the host
> > > controller device has of_node, since it is the root node for USB tree
> > > described at DT. If the host controller device is not at DT, it needs
> > > to try to get its of_node, the chipidea driver gets it through its
> > > parent node [1]
> > 
> > > 
> > > [1] https://lkml.org/lkml/2016/8/8/119
> > > 
> > 
> > Ah, this is what I was referring to in the other mail.
> > 
> > However, the way you set the of_node might be dangerous too:
> > We should generally not have two platform_device structures with
> > the same of_node pointer, most importantly it may cause the
> > child device to be bound to the same driver as the parent
> > device since the probing is done by compatible string.
> > 
> > As you tested it successfully, it must work at the moment on your
> > machine, but it could easily break depending on deferred probing
> > or module load order.
> > 
> 
> Currently, I work around above problems by setting core device of_node
> as NULL at both probe error path and platform driver .remove routine.
> 
> I admit it is not a good way, but if we only have of_node at device's
> life periods after probe, it seems ok currently. It is hard to create
> of_node dynamically when create device, and keep some contents
> of parent's of_node, and some are not.

How about turning dwc3 into a library which can be used by a range of
platform devices?  Wouldn't that solve all the current problems, and
completely avoid the need to copy resources from one platform device
to another?

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.

Thread

Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Leo Li <pku.leo@gmail.com> - 2016-09-02 00:20 +0200
  Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-02 12:50 +0200
    Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Russell King - ARM Linux <linux@armlinux.org.uk> - 2016-09-02 13:00 +0200
      Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-02 13:20 +0200
        Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-02 16:20 +0200
        Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Alan Stern <stern@rowland.harvard.edu> - 2016-09-02 16:30 +0200
          Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-02 18:00 +0200
            Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Roger Quadros <rogerq@ti.com> - 2016-09-07 09:20 +0200
              Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-07 10:30 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Roger Quadros <rogerq@ti.com> - 2016-09-07 15:10 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-07 16:40 +0200
        Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-02 18:30 +0200
    Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-02 13:00 +0200
      Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Robin Murphy <robin.murphy@arm.com> - 2016-09-02 14:00 +0200
        Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-02 15:00 +0200
        Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-02 15:20 +0200
    Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Leo Li <pku.leo@gmail.com> - 2016-09-03 00:20 +0200
      Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-05 17:50 +0200
        Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-06 08:40 +0200
          Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-06 08:50 +0200
            Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-06 12:50 +0200
              Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-06 13:00 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-06 15:30 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-07 09:00 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-07 09:50 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-07 11:00 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-07 11:30 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Russell King - ARM Linux <linux@armlinux.org.uk> - 2016-09-07 11:40 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-07 12:20 +0200
          Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-06 12:40 +0200
            Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-07 08:40 +0200
              Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-07 10:50 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-07 12:00 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Robin Murphy <robin.murphy@arm.com> - 2016-09-07 12:40 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-07 12:50 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-07 12:30 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-07 17:30 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Alan Stern <stern@rowland.harvard.edu> - 2016-09-07 18:10 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-07 21:50 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-08 03:20 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 10:10 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-08 10:10 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 10:30 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-08 10:40 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 10:50 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-08 11:50 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 12:20 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-08 13:10 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 13:20 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-08 13:30 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 13:50 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Felipe Balbi <balbi@kernel.org> - 2016-09-08 14:00 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 14:50 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-08 14:10 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 14:20 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-08 14:30 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Arnd Bergmann <arnd@arndb.de> - 2016-09-08 15:00 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-09 03:40 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Grygorii Strashko <grygorii.strashko@ti.com> - 2016-09-08 15:10 +0200
                Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent  dev Peter Chen <hzpeterchen@gmail.com> - 2016-09-09 04:00 +0200

csiph-web