[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [patch V2 43/46] genirq/msi: Provide and use msi_domain_set_default_info_flags()
- To: Marc Zyngier <maz@xxxxxxxxxx>
- From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
- Date: Fri, 28 Aug 2020 20:42:21 +0200
- Cc: LKML <linux-kernel@xxxxxxxxxxxxxxx>, x86@xxxxxxxxxx, Joerg Roedel <joro@xxxxxxxxxx>, iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx, linux-hyperv@xxxxxxxxxxxxxxx, Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>, Jon Derrick <jonathan.derrick@xxxxxxxxx>, Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>, Wei Liu <wei.liu@xxxxxxxxxx>, "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>, Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>, Steve Wahl <steve.wahl@xxxxxxx>, Dimitri Sivanich <sivanich@xxxxxxx>, Russ Anderson <rja@xxxxxxx>, linux-pci@xxxxxxxxxxxxxxx, Bjorn Helgaas <bhelgaas@xxxxxxxxxx>, Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>, xen-devel@xxxxxxxxxxxxxxxxxxxx, Juergen Gross <jgross@xxxxxxxx>, Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>, "Rafael J. Wysocki" <rafael@xxxxxxxxxx>, Megha Dey <megha.dey@xxxxxxxxx>, Jason Gunthorpe <jgg@xxxxxxxxxxxx>, Dave Jiang <dave.jiang@xxxxxxxxx>, Alex Williamson <alex.williamson@xxxxxxxxxx>, Jacob Pan <jacob.jun.pan@xxxxxxxxx>, Baolu Lu <baolu.lu@xxxxxxxxx>, Kevin Tian <kevin.tian@xxxxxxxxx>, Dan Williams <dan.j.williams@xxxxxxxxx>
- Delivery-date: Fri, 28 Aug 2020 18:42:28 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
On Thu, Aug 27 2020 at 09:17, Marc Zyngier wrote:
> On 2020-08-26 12:17, Thomas Gleixner wrote:
>> #ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
>> +void msi_domain_set_default_info_flags(struct msi_domain_info *info)
>> +{
>> + /* Required so that a device latches a valid MSI message on startup
>> */
>> + info->flags |= MSI_FLAG_ACTIVATE_EARLY;
>
> As far as I remember the story behind this flag (it's been a while),
> it was working around a PCI-specific issue, hence being located in
> the PCI code.
Yes. Some cards misbehave when there is no valid message programmed and
MSI is enabled.
> Now, the "program the MSI before enabling it" concept makes sense no
> matter what bus this is on, and I wonder why we are even keeping this
> flag around.
> Can't we just drop it together with the check in
> msi_domain_alloc_irqs()?
I'm fine with that.
Thanks,
tglx
|
