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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: sfr@canb.auug.org.au, devicetree-discuss@lists.ozlabs.org,
	linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org, davem@davemloft.net
Subject: Re: [RFC PATCH 01/15] dt/powerpc: move of_bus_type infrastructure to ibmebus
Date: Fri, 25 Feb 2011 19:53:39 +1100	[thread overview]
Message-ID: <1298624019.8833.607.camel@pasglop> (raw)
In-Reply-To: <201102241546.48790.arnd@arndb.de>

On Thu, 2011-02-24 at 15:46 +0100, Arnd Bergmann wrote:
> On Wednesday 23 February 2011, Grant Likely wrote:
> > arch/powerpc/kernel/ibmebus.c is the only remaining user of the
> > of_bus_type support code for initializing the bus and registering
> > drivers.  All others have either been switched to the vanilla platform
> > bus or already have their own infrastructure.
> > 
> > This patch moves the functionality that ibmebus is using out of
> > drivers/of/{platform,device}.c and into ibmebus.c where it is actually
> > used.  Also renames the moved symbols from of_platform_* to
> > ibmebus_bus_* to reflect the actual usage.
> > 
> > This patch is part of moving all of the of_platform_bus_type users
> > over to the platform_bus_type.
> > 
> > Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
> 
> The ibmebus is essentially the platform bus of the IBM Power Systems (a.k.a.
> pSeries a.k.a. System p), I think it would make a lot of sense to convert
> the two drivers (ehca and ehea) on this bus into platform drivers as well.
> 
> The original reason for this bus was to provide a different IOMMU for them
> than what is used on the PCI devices. This should now be possible in simpler
> ways.

Well, it's really the IBM "GX" bus but yeah, it could be converted I
suppose. The "special" iommu functions mostly derive from the fact that
the two adapters we are interested in have their own translation
mechanism built-in. The GX bus sits "above" the TCEs used as an iommu on
these systems.

> > +static void ibmebus_bus_device_shutdown(struct device *dev)
> > +{
> > +	struct platform_device *of_dev = to_platform_device(dev);
> > +	struct of_platform_driver *drv = to_of_platform_driver(dev->driver);
> > +
> > +	if (dev->driver && drv->shutdown)
> > +		drv->shutdown(of_dev);
> > +}
> 
> neither of the drivers provides a shutdown function.

Right but they might grow one ... and people will wonder why it doesn't
work if you remove the above :-)

 .../...

> These are also unused in the drivers.

Same reasoning, however it becomes moot if we convert them to platform.

Cheers,
Ben.

  reply	other threads:[~2011-02-25  8:53 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-02-23  4:33 [RFC PATCH 00/15] Remove last remains of of_platform_bus_type Grant Likely
2011-02-23  4:33 ` [RFC PATCH 01/15] dt/powerpc: move of_bus_type infrastructure to ibmebus Grant Likely
2011-02-24 14:46   ` Arnd Bergmann
2011-02-25  8:53     ` Benjamin Herrenschmidt [this message]
2011-02-28  7:35     ` Grant Likely
2011-02-23  4:33 ` [RFC PATCH 02/15] dt: add a match table pointer to struct device Grant Likely
2011-02-23 18:29   ` Rob Herring
2011-02-23 18:44     ` Grant Likely
2011-02-23 21:18     ` Open Firmware and interrupt trigger Robert Thorhuus
2011-02-24 20:46       ` Benjamin Herrenschmidt
2011-02-25  7:29         ` Robert Thorhuus
2011-02-25  8:47           ` Benjamin Herrenschmidt
2011-02-23  4:33 ` [RFC PATCH 03/15] dt/powerpc: Eliminate users of of_platform_{, un}register_driver Grant Likely
2011-02-23  4:33 ` [RFC PATCH 04/15] dt/sparc: " Grant Likely
2011-02-23  4:34 ` [RFC PATCH 05/15] leds/leds-gpio: merge platform_driver with of_platform_driver Grant Likely
2011-02-23  4:34 ` [RFC PATCH 06/15] dt: xilinx_hwicap: merge platform and of_platform driver bindings Grant Likely
2011-02-25 18:25   ` [RFC PATCH 06/15] dt: xilinx_hwicap: merge platform and of_platformdriver bindings Stephen Neuendorffer
2011-02-28  7:41     ` Grant Likely
2011-02-23  4:34 ` [RFC PATCH 07/15] dt: uartlite: merge platform and of_platform driver bindings Grant Likely
2011-02-23  8:58   ` Peter Korsgaard
2011-02-23 18:10     ` Grant Likely
2011-02-23  4:34 ` [RFC PATCH 08/15] dt/spi: Eliminate users of of_platform_{, un}register_driver Grant Likely
2011-02-23  4:34 ` [RFC PATCH 09/15] dt/sound: " Grant Likely
2011-02-23  4:34 ` [RFC PATCH 10/15] dt/net: " Grant Likely
2011-02-23  4:34 ` [RFC PATCH 11/15] dt/video: " Grant Likely
2011-02-23  4:34 ` [RFC PATCH 12/15] dt/usb: " Grant Likely
2011-02-23  4:34 ` [RFC PATCH 13/15] dt/serial: " Grant Likely
2011-02-24 16:34   ` Arnd Bergmann
2011-02-23  4:34 ` [RFC PATCH 14/15] dt: Eliminate of_platform_{,un}register_driver Grant Likely
2011-02-23 16:56   ` Rob Herring
2011-02-23 17:22     ` Grant Likely
2011-02-23  4:34 ` [RFC PATCH 15/15] dt: eliminate of_platform_driver shim code Grant Likely

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