From: pratyush.anand@st.com (pratyush)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V7 02/17] SPEAr13xx: Add PCIe host controller base driver support.
Date: Wed, 13 Apr 2011 17:41:14 +0530 [thread overview]
Message-ID: <4DA592E2.1060206@st.com> (raw)
In-Reply-To: <201104111722.18309.arnd@arndb.de>
Hello Arnd,
>>
>> Sorry, may be I could not get this point correctly. Do you mean that,
>> I should create a static mapping for IN0_MEM_SIZE (200 MB) and
>> IN_IO_SIZE (20 MB) during board initialization itself?
>
> Only IN_IO_SIZE. The I/O space is implicitly assumed to be mapped, while
> the memory space is mapped by device drivers individually.
>
Ok.. will do it..
>>> Please reread my previous comments. You have to redefine __io() in order to make
>>> the I/O port accesses work. When you do that, you cannot define
>>> __io_address (which is used by non-PCI code) as using __io.
>>>
>>
>> __io_address is not used by PICe routines. Also, this is not part of
>> this patch.
>
> Yes, that was my point.
>
ok..
>>> Is IN_IO_SIZE per host, or this shared across all hosts?
>>
>> This is per host. So is it not a practical size?
>> What should be a reasonable IO size?
>
> 64 KB is more than enough per host. That is the maximum that an x86 PC
> can address, so devices usually use very little of this, if anything.
>
> There are some advantages to using 64KB combined for all hosts, but
> the easiest way should probably be to reserve 1 MB for the space
> and use 64 KB for each of them.
>
> If you have a PCI-ISA bridge chip or a card that has one, it needs to
> be on a host that has its I/O space in the first 64 KB.
>
I will modify, as you have suggested!!!
regards
Pratyush
next prev parent reply other threads:[~2011-04-13 12:11 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1298977728.git.viresh.kumar@st.com>
2011-03-23 4:52 ` [PATCH V7 02/17] SPEAr13xx: Add PCIe host controller base driver support Viresh Kumar
2011-03-23 8:28 ` Arnd Bergmann
2011-04-11 12:26 ` pratyush
2011-04-11 15:22 ` Arnd Bergmann
2011-04-13 12:11 ` pratyush [this message]
2011-04-12 15:32 ` Rob Herring
2011-04-13 12:25 ` pratyush
2011-04-17 20:19 ` Arnd Bergmann
2011-04-27 6:52 ` Pratyush Anand
2011-04-27 9:03 ` Arnd Bergmann
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