From: Lukas Wunner <lukas@wunner.de>
To: "Raj, Ashok" <ashok.raj@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
Sathyanarayanan Kuppuswamy Natarajan
<sathyanarayanan.nkuppuswamy@gmail.com>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Bjorn Helgaas <bhelgaas@google.com>,
Linux PCI <linux-pci@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Keith Busch <kbusch@kernel.org>,
knsathya@kernel.org, Sinan Kaya <okaya@kernel.org>
Subject: Re: [PATCH v2 1/1] PCI: pciehp: Skip DLLSC handling if DPC is triggered
Date: Wed, 17 Mar 2021 20:40:09 +0100 [thread overview]
Message-ID: <20210317194009.GA9515@wunner.de> (raw)
In-Reply-To: <20210317192241.GE52280@otc-nc-03>
On Wed, Mar 17, 2021 at 12:22:41PM -0700, Raj, Ashok wrote:
> On Wed, Mar 17, 2021 at 08:09:52PM +0100, Lukas Wunner wrote:
> > On Wed, Mar 17, 2021 at 10:45:21AM -0700, Dan Williams wrote:
> > > Ah, ok, we're missing a flush of the hotplug event handler after the
> > > link is up to make sure the hotplug handler does not see the Link Up.
> > > I'm not immediately seeing how the new proposal ensures that there is
> > > no Link Up event still in flight after DPC completes its work.
> > > Wouldn't it be required to throw away Link Up to Link Up transitions?
> >
> > If you look at the new code added to pciehp_ist() by my patch...
> >
> > atomic_and(~PCI_EXP_SLTSTA_DLLSC, &ctrl->pending_events);
> > if (pciehp_check_link_active(ctrl) > 0)
> > events &= ~PCI_EXP_SLTSTA_DLLSC;
>
> When you have a Surprise Link Down and without any DPC, the link trains
> back up. Aren't we expected to take the slot down and add it as if a remove
> and add happens?
>
> without this change if slot-status == ON_STATE, DLLSC means we would power
> the slot off. Then we check link_active and bring the slot back on isn't
> it?
Yes to both questions. That behavior should still be the same
with the patch. Do you think it's not?
next prev parent reply other threads:[~2021-03-17 19:40 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-13 3:32 [PATCH v2 1/1] PCI: pciehp: Skip DLLSC handling if DPC is triggered sathyanarayanan.kuppuswamy
2021-03-13 3:35 ` Kuppuswamy, Sathyanarayanan
2021-03-17 4:13 ` Lukas Wunner
2021-03-17 5:08 ` Dan Williams
2021-03-17 5:31 ` Lukas Wunner
2021-03-17 16:31 ` Dan Williams
2021-03-17 17:19 ` Sathyanarayanan Kuppuswamy Natarajan
2021-03-17 17:45 ` Dan Williams
2021-03-17 17:54 ` Sathyanarayanan Kuppuswamy Natarajan
2021-03-17 19:01 ` Lukas Wunner
2021-03-17 20:02 ` Kuppuswamy, Sathyanarayanan
2021-03-18 15:35 ` Sinan Kaya
2021-03-28 9:53 ` Lukas Wunner
2021-03-17 19:09 ` Lukas Wunner
2021-03-17 19:22 ` Raj, Ashok
2021-03-17 19:40 ` Lukas Wunner [this message]
2021-03-28 5:49 ` Kuppuswamy, Sathyanarayanan
2021-03-28 9:07 ` Lukas Wunner
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