From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm@xmission.com (Eric W. Biederman) Subject: Re: [Dri-devel] Re: DRM and pci_driver conversion Date: 27 Oct 2003 08:10:16 -0700 Sender: linux-fbdev-devel-admin@lists.sourceforge.net Message-ID: References: Mime-Version: 1.0 Return-path: In-Reply-To: Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: List-Unsubscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Linus Torvalds Cc: Egbert Eich , Jon Smirl , kronos@kronoz.cjb.net, Kernel Mailing List , linux-fbdev-devel@lists.sourceforge.net, dri-devel , Jeff Garzik Linus Torvalds writes: > On Sat, 25 Oct 2003, Egbert Eich wrote: > > > > Speaking of XFree86: when I developed the PCI resource stuff in > > XFree86 I was trying to get support from kernel folks to get the > > appropriate user space interfaces into the kernel. When I got > > nowhere I decided to do everything myself. > > There won't be any "user space interfaces". There are perfectly good > in-kernel interfaces, and anybody who needs them needs to be in kernel > space. Ie the kernel interfaces are for kernel modules, not for user space > accesses. Well almost. There is still one significant flaw in the kernel space stuff. The BIOS can specify arbitrary regions as reserved in the E820 map and then a kernel driver can't use that region itself. This shows up in corner cases where the resource on the PCI device is a boolean rather than a general purpose thing. Particularly for mtd map drivers to allow flashing your ROM from linux this is a problem. This is not required for 2.6.0 but it would be nice to actually be able to reliably reserve resources in kernel drivers. Eric ------------------------------------------------------- This SF.net email is sponsored by: The SF.net Donation Program. Do you like what SourceForge.net is doing for the Open Source Community? Make a contribution, and help us add new features and functionality. Click here: http://sourceforge.net/donate/