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

From	Arnd Bergmann <arnd@arndb.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev
Date	2016-09-07 11:00 +0200
Message-ID	<seGS5-5U1-21@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>
Organization	linux.* mail to news gateway

Show all headers | View raw

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.

	Arnd

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