From: Sergei Shtylyov <sshtylyov@ru•mvista.com>
To: Alan <alan@lxorguk•ukuu.org.uk>
Cc: Olaf Hering <olaf@aepfle•de>,
linuxppc-dev@ozlabs•org, greg@kroah•com,
linux-ide@vger•kernel.org, linux-pci@atrey•karlin.mff.cuni.cz
Subject: Re: What is the correct way to indicate an unassigned PCI resource ?
Date: Mon, 04 Dec 2006 17:34:38 +0300 [thread overview]
Message-ID: <457431FE.6040702@ru.mvista.com> (raw)
In-Reply-To: <20061204142201.68d9621f@localhost.localdomain>
Hello.
Alan wrote:
>>>Both PCI core and IDE interpret a zero length resource as unassigned.
>> This is not about 0-length resource, this is about 0-address. Look at
>>ide_hwif_confiure() in drivers/ide/setup-pci.c...
> The discussion I was having was about sl82cxx and handling unassigned
> resources. The zero address isn't relevant to that.
You were following up to the particular error message emitted by the IDE
core (which you've now deleted), so I corrected you on its reason, that's all.
>> You should know that the IRQ assumption is *not* true even for x86 since
>>IRQ0 is and has always been a perfectly valid IRQ (used by PIT).
> Please see previous million recyclings of that discussion and Linus
> answer.
When Linus remaps IRQ0 on x86, I'll follow that code as a testament. Until
this happens, I consider is just an opinion. Forcing every arch but x86 to
remap IRQ0 is an example of the double standards.
>>>Stick a real IDE resource at zero
>> > and drivers/ide can't cope.
>> Yeah, I've noticed. Unfortunately, a lot of PPC platforms (at least) are
>>doing exactly this...
> The checks need pushing upwards and removing from their current place -
> the pci layer should check the resource length, the isa pnp should I
> believe check for zero address etc.
So, it's OK to remove the base *address* check in ide_hwif_confiure()
altogether?
> libata makes a similar assumption in ata_resources_present() as someone
> (GregKH ???) needs to define what the proper way to encode "resource not
> allocated" into the PCI resources should be.
> If someone on the PCI list (cc'd) or Greg can give a definitive answer then we can go fix the
> offenders now.
Well, I thought that was IORESOURCE_UNSET...
> Alan
WBR, Sergei
next prev parent reply other threads:[~2006-12-04 14:33 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-11-30 16:52 pata_sl82c105 can not reserve IO region Olaf Hering
2006-11-30 17:10 ` Alan
2006-11-30 18:47 ` Olaf Hering
2006-12-01 18:34 ` Olaf Hering
2006-12-01 18:58 ` Alan
2006-12-01 19:05 ` Sergei Shtylyov
2006-12-01 21:53 ` Benjamin Herrenschmidt
2006-12-01 22:15 ` Alan
2006-12-01 22:19 ` Benjamin Herrenschmidt
2006-12-02 14:36 ` U-Boot allocating PCI I/O space from 0 (Was: pata_sl82c105 can not reserve IO region) Sergei Shtylyov
2006-12-02 16:33 ` Sergei Shtylyov
2006-12-26 20:53 ` [U-Boot-Users] " Sergei Shtylyov
2006-12-03 23:39 ` pata_sl82c105 can not reserve IO region Alan
2006-12-03 17:12 ` Olaf Hering
2006-12-03 22:24 ` Olaf Hering
2006-12-03 23:23 ` Alan
2006-12-04 0:30 ` Olaf Hering
2006-12-04 9:21 ` Olaf Hering
2006-12-03 23:07 ` Alan
2006-12-04 12:38 ` [PATCH] mark PCI resource with start 0 as unassigned Olaf Hering
2006-12-04 12:44 ` Segher Boessenkool
2006-12-04 12:50 ` Sergei Shtylyov
2006-12-04 12:54 ` Segher Boessenkool
2006-12-04 13:08 ` Sergei Shtylyov
2006-12-04 13:21 ` Alan
2006-12-04 13:25 ` Segher Boessenkool
2006-12-04 14:15 ` Alan
2007-08-01 14:22 ` Sergei Shtylyov
2007-08-01 15:51 ` Alan Cox
2007-08-06 18:04 ` Segher Boessenkool
2007-08-06 19:52 ` Alan Cox
2007-08-06 22:14 ` Benjamin Herrenschmidt
2006-12-04 13:27 ` Sergei Shtylyov
2006-12-04 14:22 ` What is the correct way to indicate an unassigned PCI resource ? Alan
2006-12-04 14:34 ` Sergei Shtylyov [this message]
2006-12-04 14:44 ` Alan
2006-12-04 15:40 ` Sergei Shtylyov
2006-12-04 15:55 ` Sergei Shtylyov
2006-12-04 20:53 ` Guennadi Liakhovetski
2006-12-05 4:43 ` Benjamin Herrenschmidt
2006-12-05 4:41 ` Benjamin Herrenschmidt
2006-12-05 8:15 ` Olaf Hering
2006-12-05 20:19 ` Benjamin Herrenschmidt
2006-12-05 21:26 ` Sergei Shtylyov
2007-01-04 17:49 ` Olaf Hering
2007-01-04 21:30 ` Benjamin Herrenschmidt
2007-01-05 10:26 ` Olaf Hering
2007-01-05 12:05 ` Benjamin Herrenschmidt
2006-12-05 10:51 ` Gabriel Paubert
2006-12-05 12:38 ` Sergei Shtylyov
2006-12-05 17:37 ` Grant Grundler
2006-12-05 19:22 ` Sergei Shtylyov
2006-12-04 12:56 ` [PATCH] mark PCI resource with start 0 as unassigned Olaf Hering
2006-12-04 13:05 ` Segher Boessenkool
2006-12-04 12:47 ` Sergei Shtylyov
2006-12-04 12:40 ` [PATCH] add delay around sl82c105_reset_engine calls Olaf Hering
2006-12-04 13:02 ` Alan
2006-12-04 13:12 ` Olaf Hering
2007-01-04 6:42 ` Olaf Hering
2007-01-04 10:53 ` Alan
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