From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Mon, 28 May 2012 16:39:47 +0300
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jan Kiszka <jan.kiszka@web.de>
Cc: "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Alexey Kardashevskiy <aik@ozlabs.ru>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Alex Williamson <alex.williamson@redhat.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	David Gibson <david@gibson.dropbear.id.au>,
	Alexander Graf <agraf@suse.de>, kvm <kvm@vger.kernel.org>
Subject: Re: [PATCH] PCI: Mark INTx masking support of Chelsio T310 10GbE NIC
 as broken
Message-ID: <20120528133946.GA23024@redhat.com>
References: <4FBF90E5.8030800@siemens.com>
 <20120528123934.GB21778@redhat.com>
 <4FC374CD.5000509@web.de>
 <20120528132109.GB22623@redhat.com>
 <4FC37DD6.7090000@web.de>
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On Mon, May 28, 2012 at 03:29:58PM +0200, Jan Kiszka wrote:
> On 2012-05-28 15:21, Michael S. Tsirkin wrote:
> > On Mon, May 28, 2012 at 02:51:25PM +0200, Jan Kiszka wrote:
> >> On 2012-05-28 14:39, Michael S. Tsirkin wrote:
> >>> On Fri, May 25, 2012 at 11:02:13AM -0300, Jan Kiszka wrote:
> >>>> According to Alexey, the T310 does not properly support INTx masking as
> >>>> it fails to keep the PCI_STATUS_INTERRUPT bit updated once the interrupt
> >>>> is masked. Mark this adapter as broken so that pci_intx_mask_supported
> >>>> won't report it as compatible.
> >>>>
> >>>> Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
> >>>> Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
> >>>
> >>>
> >>> Just a thought: would be nice to have a way to discover
> >>> the quirk was activated. Add an attribute so that
> >>> userspace can detect and report this properly to users?
> >>> Or just log a warning message ...
> >>
> >> pr_notice_once?
> > 
> > OK IMO.
> > 
> >> A flag for userspace would be significantly more
> >> complicated (and not PCI layer hands).
> > 
> > Why not? I meant e.g. an attribute in pci-sysfs.
> 
> Possible. But what is the preferred way of doing this? Are there any
> precedences?
> 
> Jan
> 

E.g. a reset attribute is there only if device reset is supported.
I don't insist on this - merely asking how does userspace report
an attempt to share IRQs and whether the reason is
discoverable in some way.

-- 
MST