[alsa-devel] a7839e96 (PNP: increase max resources) breaks my ALSA intel8x0 sound card

[Andrew Morton]

On Sun, 27 Jan 2008 12:17:17 -0600
Robert Hancock <hancockr at shaw.ca> wrote:

> Avuton Olrich wrote:
> > With v2.6.24 my second ALSA sound device stopped working.
> > 
> > After bisection it says this was the offending commit.
> > 
> > a7839e960675b549f06209d18283d5cee2ce9261 is first bad commit
> > commit a7839e960675b549f06209d18283d5cee2ce9261
> > Author: Zhao Yakui <yakui.zhao at intel.com>
> > Date:   Wed Nov 28 16:21:21 2007 -0800
> > 
> >     PNP: increase the maximum number of resources
> > 
> >     On some systems the number of resources(IO,MEM) returnedy by PNP device is
> >     greater than the PNP constant, for example motherboard devices.  It brings
> >     that some resources can't be reserved and resource confilicts.  This will
> >     cause PCI resources are assigned wrongly in some systems, and cause hang.
> >     This is a regression since we deleted ACPI motherboard driver and use PNP
> >     system driver.
> > 
> >     [akpm at linux-foundation.org: fix text and coding-style a bit]
> >     Signed-off-by: Li Shaohua <shaohua.li at intel.com>
> >     Signed-off-by: Zhao Yakui <yakui.zhao at intel.com>
> >     Cc: Bjorn Helgaas <bjorn.helgaas at hp.com>
> >     Cc: Thomas Renninger <trenn at suse.de>
> >     Cc: <stable at kernel.org>
> >     Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
> >     Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
> > 
> > The audio device is 00:1b.0 (see my lspci -vvv output), the other
> > audio device works fine.
> > 
> > http://avuton.googlepages.com/v2.6-before (dmesg revision before)
> > http://avuton.googlepages.com/v2.6-after (dmesg broken revision)
> > http://avuton.googlepages.com/lspci-vvv
> > http://avuton.googlepages.com/config (from the broken revision)
> > http://avuton.googlepages.com/iomem
> > http://avuton.googlepages.com/ioports

I don't think anything has happened yet on this?

> Here's why the driver fails to load:
> 
> [   31.133060] ACPI: PCI Interrupt 0000:00:1b.0[A] -> GSI 22 (level, 
> low) -> IRQ 22
> [   31.133141] PCI: Unable to reserve mem region #1:4000 at febf8000 for 
> device 0000:00:1b.0
> [   31.133197] ACPI: PCI interrupt for device 0000:00:1b.0 disabled
> [   31.133244] HDA Intel: probe of 0000:00:1b.0 failed with error -16
> 
> The iomem location of the HDA controller conflicts with this reservation 
> by the BIOS:
> 
> [   22.906654] system 00:08: iomem range 0xfebfa000-0xfebfac00 has been 
> reserved
> 
> There was a patch floating around to ignore PnPACPI reservations which 
> conflict with PCI BARs, which appears to be what's happening in this 
> case. That patch originally worked for any board, but was later made 
> specific to a certain Supermicro motherboard which had the sata_nv 
> controller MMIO regions marked as reserved, preventing the driver from 
> loading. We may need a more general solution. See:
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=313491

Thanks.  If we were to remove the supermicro-specificity, would this be a
sufficiently general solution?