From: Bjorn Helgaas <helgaas@kernel.org>
To: Christoph Hellwig <hch@lst.de>
Cc: agordeev@redhat.com, linux-pci@vger.kernel.org,
davem@davemloft.net, shane.huang@amd.com
Subject: Re: [PATCH, RFC] PCI: use pci_intx_for_msi in pci_alloc_irq_vectors
Date: Tue, 20 Sep 2016 14:46:14 -0500 [thread overview]
Message-ID: <20160920194614.GE4941@localhost> (raw)
In-Reply-To: <1473577767-9888-1-git-send-email-hch@lst.de>
Hi Christoph,
On Sun, Sep 11, 2016 at 09:09:27AM +0200, Christoph Hellwig wrote:
> Alex pointed out that we might want to use pci_intx_for_msi in
> pci_alloc_irq_vectors for the case where allocating MSI or MSI-X vectors
> fails completely. I tried to read up the history behind pci_intx_for_msi,
> but the changelogs seem a bit confusing, e.g. the comment in the tg3
> around that code that was replaced by this quirk only talk about
> _disabling_ INT-X. Maybe someone can help me to shed some light about
> this workaround, and help answering the question wether we need it
> in this case.
If we want to do this, I'd like to have a changelog that explains
*why*, so I'm ignoring it for now. I'm not nacking it; I just don't
understand why we should do it yet, and I'm too lazy to do all the
research myself.
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Cc: David Miller <davem@davemloft.net>
> Cc: Shane Huang <shane.huang@amd.com>
> ---
> drivers/pci/msi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index 9da5ecb..a4b443f 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -1215,7 +1215,7 @@ int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,
>
> /* use legacy irq if allowed */
> if ((flags & PCI_IRQ_LEGACY) && min_vecs == 1) {
> - pci_intx(dev, 1);
> + pci_intx_for_msi(dev, 1);
> return 1;
> }
>
> --
> 2.1.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2016-09-20 19:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-11 7:09 [PATCH, RFC] PCI: use pci_intx_for_msi in pci_alloc_irq_vectors Christoph Hellwig
2016-09-20 19:46 ` Bjorn Helgaas [this message]
2016-09-20 20:03 ` Christoph Hellwig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160920194614.GE4941@localhost \
--to=helgaas@kernel.org \
--cc=agordeev@redhat.com \
--cc=davem@davemloft.net \
--cc=hch@lst.de \
--cc=linux-pci@vger.kernel.org \
--cc=shane.huang@amd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).