From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shaohua Li Subject: Re: Re: [PATCH] PNPACPI: handle address descriptors in _PRS Date: Fri, 23 Sep 2005 08:55:01 +0800 Message-ID: <1127436901.3933.0.camel@linux-hp.sh.intel.com> References: <200509210927.03377.bjorn.helgaas@hp.com> <1127350144.3961.5.camel@linux-hp.sh.intel.com> <200509221748.30090.bjorn.helgaas@hp.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200509221748.30090.bjorn.helgaas-VXdhtT5mjnY@public.gmane.org> Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Bjorn Helgaas Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, Matthieu Castet , Adam Belay , "Luck, Tony" List-Id: linux-acpi@vger.kernel.org On Thu, 2005-09-22 at 17:48 -0600, Bjorn Helgaas wrote: > On Wednesday 21 September 2005 6:49 pm, Shaohua Li wrote: > > On Wed, 2005-09-21 at 23:27 +0800, Bjorn Helgaas wrote: > > > On Tuesday 20 September 2005 7:17 pm, Shaohua Li wrote: > > > > On Tue, 2005-09-20 at 16:26 -0600, Bjorn Helgaas wrote: > > > > > PNPACPI complained about and ignored devices with ADDRESS16, > > > ADDRESS32, > > > > > or ADDRESS64 descriptors in _PRS. Those descriptors seem > > > legitimate, > > > > > and HP firmware uses them for built-in serial ports, so this patch > > > adds > > > > > support for them. > > > > > > > You might have missed the similar change in pnpacpi_encode_resources > > > in > > > > your patch. It's used when we assign new resources (_SRS method) to > > > pnp > > > > devices. > > > > > > You're right, I did miss the corresponding encoding change. I'll > > > add that. I feel a bit uneasy about it, though, because it will be > > > a fair amount of code, and I don't know how to test it. Do we ever > > > really use _SRS today? And there's information lost when decoding > > > the ACPI resources, such as the _TRA. > > We did use _SRS, at least under x86. This only is done when some PNP > > devices havn't resources, so only very small number of systems need it. > > Ignoring it might be ok currently, if HP firmware always assigns > > resources to PNP devices. Yes, we did lose the info of _TRA. I didn't > > find any system uses it. Maybe some big IA64 systems use. > > HP ia64 systems definitely use _TRA. I would expect most systems > with multiple PCI root bridges would use _TRA, because if you > don't, the amount of 32-bit PCI bus address space you can use > is severely limited. > > HP firmware does assign resources to the PNP devices (typically > they're things hardwired onto the motherboard at fixed addresses). > So we don't actually need the encoding changes at the moment. > > I'm inclined to just leave the encoding out for now. That > way, we don't carry around the untested code, and if somebody > eventually tries to use it, the attempt to set resources will > fail, and we can write the code and test it at that time. Ok, lets wait till it actually is used. Thanks, Shaohua ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php