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SubjectRe: Ricoh DMAR bug returns? (WAS Re: [PATCH v4] Quirk for buggy dma source tags with Intel IOMMU.)
On 04/05/2013 12:44 AM, Andrew Cooks wrote:
> On Tue, Apr 2, 2013 at 11:47 PM, Pat Erley <pat-lkml@erley.org> wrote:
>> On 04/02/2013 10:50 AM, Andrew Cooks wrote:
>>>
>>> On 2 Apr 2013 15:37, "Pat Erley" <pat-lkml@erley.org
>>> <mailto:pat-lkml@erley.org>> 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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