Re: Ricoh DMAR bug returns? (WAS Re: [PATCH v4] Quirk for buggy dmasource tags with Intel IOMMU.)

[Pat Erley]

On 04/05/2013 12:44 AM, Andrew Cooks wrote:
> On Tue, Apr 2, 2013 at 11:47 PM, Pat Erley <pat-lkml@xxxxxxxxx> wrote:
> > On 04/02/2013 10:50 AM, Andrew Cooks wrote:
> > > On 2 Apr 2013 15:37, "Pat Erley" <pat-lkml@xxxxxxxxx
> > > <mailto:pat-lkml@xxxxxxxxx>> wrote:
> > >   >
> > >   > On 03/07/2013 09:35 PM, Andrew Cooks wrote:
> > >   >>
> > >   >> --- a/drivers/pci/quirks.c
> > >   >> +++ b/drivers/pci/quirks.c
> > >   >>
> > >   >> +/* Table of multiple (ghost) source functions. This is similar to the
> > >   >> + * translated sources above, but with the following differences:
> > >   >> + * 1. the device may use multiple functions as DMA sources,
> > >   >> + * 2. these functions cannot be assumed to be actual devices,
> > > they're simply
> > >   >> + * incorrect DMA tags.
> > >   >> + * 3. the specific ghost function for a request can not always be
> > > predicted.
> > >   >> + * For example, the actual device could be xx:yy.1 and it could use
> > >   >> + * both 0 and 1 for different requests, with no obvious way to tell
> > > when
> > >   >> + * DMA will be tagged as comming from xx.yy.0 and and when it will
> > > be tagged
> > >   >> + * as comming from xx.yy.1.
> > >   >> + * The bitmap contains all of the functions used in DMA tags,
> > > including the
> > >   >> + * actual device.
> > >   >> + * See https://bugzilla.redhat.com/show_bug.cgi?id=757166,
> > >   >> + * https://bugzilla.kernel.org/show_bug.cgi?id=42679
> > >   >> + * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1089768
> > >   >> + */
> > >   >> +static const struct pci_dev_dma_multi_func_sources {
> > >   >> +       u16 vendor;
> > >   >> +       u16 device;
> > >   >> +       u8 func_map;    /* bit map. lsb is fn 0. */
> > >   >> +} pci_dev_dma_multi_func_sources[] = {
> > >   >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9123, (1<<0)|(1<<1)},
> > >   >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9125, (1<<0)|(1<<1)},
> > >   >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9128, (1<<0)|(1<<1)},
> > >   >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9130, (1<<0)|(1<<1)},
> > >   >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9143, (1<<0)|(1<<1)},
> > >   >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9172, (1<<0)|(1<<1)},
> > >   >> +       { 0 }
> > >   >> +};
> > >   >
> > >   >
> > >   > Adding another buggy device.  I have a Ricoh multifunction device:
> > >   >
> > >   > 17:00.0 SD Host controller: Ricoh Co Ltd MMC/SD Host Controller (rev
> > > 01)
> > >   > 17:00.3 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 PCIe IEEE 1394
> > >   >         Controller (rev 01)
> > >   >
> > >   > 17:00.0 0805: 1180:e822 (rev 01)
> > >   > 17:00.3 0c00: 1180:e832 (rev 01)
> > >   >
> > >
> > > The Ricoh device issue has been known for some time and a quirk has been
> > > available since commit 12ea6cad1c7d046 in June 2012.  It's slightly
> > > different than the problem this patch tries to work around [1].
> >
> >
> > Hmm, I've had this problem with many recent (vanilla) kernels, up to and
> > including 3.9-rc5
> >
> >
> > >   > that adding entries for also fixed booting.  I don't have any SD
> > > cards or firewire devices handy to test that they work, but the system
> > > now boots, which was not the case without your patch and IOMMU/DMAR
> > > enabled.
> > >
> > > That is really strange. Could you tell us what kernel version you tested
> > > and provide dmesg output?
> >
> >
> > I'll capture a vanilla 3.8.5 boot without any patches and iommu=off, then
> > try to find another machine to catch what I can of a netconsole boot with
> > iommu=on.  What's the preferred way to send these?  pastebin links?
> >
> > I'd been running the 'dirty' fix that's in the redhat bugzilla entry.  I
> > checked my .config and have CONFIG_PCI_QUIRKS=y, and verified my devices are
> > in the quirks table for the pci_func_0_dma_source fixup.
> Do you mean that even though your hardware is specifically listed in
> the quirk table, the quirk simply hasn't worked for you? That would be
> unfortunate, to say the least.

Precisely.

> The fedora kernel included a separate patch for this issue until
> recently (see https://bugzilla.redhat.com/show_bug.cgi?id=880051).  It
> basically just disabled DMAR when the Ricoh device is present, the
> same as the patch to the mailing list you mentioned.

Yes, that's what I've been avoiding doing.  Every new release, I boot 
once with iommu=on, and firewire blacklisted, boot up, load the firewire 
driver.  This has caused the 'Ricoh DMAR' bug on every kernel since I 
got the laptop.  I then reboot and ....

> Is the dirty fix you're referring to comment 7?
> https://bugzilla.redhat.com/show_bug.cgi?id=605888#c7

Apply this patch, which has worked fine for me, but per a commend in a 
thread I created here on 10/19/2012[1], this has a potential significant 
performance impact.  In my use case, a performance hit is worth the cost 
for the features.

However, your patch(while not intended to be the fix), actually solves 
the issue on my machine.  I don't know if it also has the potential 
performance impact, but it's certainly not noticeably worse in my use case.

Pat Erley

[1] http://marc.info/?l=linux-pci&m=135094489232548&w=2
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