From: Jeff Garzik <jgarzik@pobox.com>
To: Sergei Shtylylov <sshtylyov@ru.mvista.com>
Cc: netdev@vger.kernel.org, Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH] Don't call request_region() for 3C90x chips
Date: Wed, 19 Jul 2006 13:57:37 -0400 [thread overview]
Message-ID: <44BE7291.2080306@pobox.com> (raw)
In-Reply-To: <200607102225.49253.sshtylyov@ru.mvista.com>
Sergei Shtylylov wrote:
> It's generally not a good idea to call request_region() on an address returned
> by pci_iomap(), even less so on a MMIO address. And there was absolutely no
> point in claiming the region already claimed by the PCI core, especially with
> the same PCI generic owner's name. As this is the only case of the
> must_free_region flag being set, this flag may go away as well...
>
> Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
I agree you have identified a bug, but this is not a solution.
The current driver bug is that it calls request_region() potentially on
an MMIO address, but the solution is _not_ to completely avoid reserving
the resource.
The region registered with the PCI core, but _not_ claimed by anyone.
Someone still needs to either call pci_{request,release}_regions() or
request_[mem_]region() to indicate that the resource is reserved.
This bug you have found was probably a missed detail during the
conversion to the iomap API.
Jeff
next prev parent reply other threads:[~2006-07-19 17:57 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-10 18:25 [PATCH] Don't call request_region() for 3C90x chips Sergei Shtylylov
2006-07-19 17:57 ` Jeff Garzik [this message]
2006-07-19 19:08 ` Sergei Shtylyov
2006-07-19 19:22 ` Jeff Garzik
2006-07-27 19:22 ` Sergei Shtylyov
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