Messages in this thread | | | Date | Tue, 12 Feb 2013 19:58:16 +0100 | From | Thomas Petazzoni <> | Subject | Re: [PATCH 05/32] lib: devres: don't enclose pcim_*() functions in CONFIG_HAS_IOPORT |
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Dear Arnd Bergmann,
On Tue, 12 Feb 2013 18:00:48 +0000, Arnd Bergmann wrote: > On Tuesday 12 February 2013, Thomas Petazzoni wrote: > > The pcim_*() functions are used by the libata-sff subsystem, and > > this subsystem is used for many SATA drivers on ARM platforms that > > do not necessarily have I/O ports. > > > > Signed-off-by: Thomas Petazzoni > > <thomas.petazzoni@free-electrons.com> Cc: Paul Gortmaker > > <paul.gortmaker@windriver.com> Cc: Jesse Barnes > > <jbarnes@virtuousgeek.org> Cc: Yinghai Lu <yinghai@kernel.org> > > Cc: linux-kernel@vger.kernel.org > > Sorry, but this patch is still incorrect.
I know, but the discussion was so huge on the first posting that it was basically impossible to draw a conclusion out of it.
> Any driver that requires a > linear mapping of I/O ports to __iomem pointers must depend > CONFIG_HAS_IOPORT with the current definition of that symbol (as > mentioned before, we should really rename that to > CONFIG_HAS_IOPORT_MAP). Having these functions not defined is a > compile time check that is necessary to ensure that all drivers have > the correct annotation.
I have the feeling that the problem is more complex than that. My understanding is that the pcim_iomap_regions() function used by drivers/ata/libata-sff.c can perfectly be used to map memory BARs, and not necessarily I/O BARs. Therefore, this driver can perfectly be used in an architecture where CONFIG_NO_IOPORT is selected.
The thing is that pcim_iomap_regions() transparently allows to remap an I/O BAR is such a BAR is passed as argument, or a memory BAR if such a BAR is passed as argument.
Therefore, I continue to believe that the pcim_*() functions are useful even if the platform doesn't have CONFIG_HAS_IOPORT.
Best regards,
Thomas -- Thomas Petazzoni, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com
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