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From: "Spassov, Stanislav" <stanspas@amazon.de>
To: "ashok.raj@intel.com" <ashok.raj@intel.com>
Cc: "corbet@lwn.net" <corbet@lwn.net>,
	"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
	"lkp@intel.com" <lkp@intel.com>,
	"okaya@kernel.org" <okaya@kernel.org>,
	"tglx@linutronix.de" <tglx@linutronix.de>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"Schoenherr, Jan H." <jschoenh@amazon.de>,
	"rajatja@google.com" <rajatja@google.com>,
	"linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
	"bhelgaas@google.com" <bhelgaas@google.com>,
	"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>
Subject: Re: [PATCH v3 16/17] PCI: Add CRS handling to pci_dev_wait()
Date: Fri, 6 Mar 2020 18:07:24 +0000	[thread overview]
Message-ID: <c273cb0c448781cdb42932e3dd324a30668cee65.camel@amazon.de> (raw)
In-Reply-To: <20200305175620.GA94051@otc-nc-03>

> > IF CRS is supported by Root Port but CRS SV is not enabled, the request
> > is retried autonomously by the Root Port. Platform-specific configuration
> > registers may exist to limit the number of or time taken by such retries.
> 
> Also when CRSV is enabled, config read that doesn't cover VENDOR is
> also retried automatically.
> 

Agreed. This is explained in the very next sentence of the commit message,
but I will see if I can re-order/re-phrase to make the explanation less confusing.

> > 
> > +     if (dev->crssv_enabled) {
> > +             u32 id;
> 
> I like this check to read VENDOR_ID when crssv is enabled. But your patches
> seems to define in patch13 and used in patch16?
> 
> can we keep them simple? and if possible just this would be a
> needed fix. We have some systems that we have found can cause
> timeouts if CRSV is enabled, but you read any other register
> other than the PCI_VENDOR.
> 
> Would prefer to see this fix before the other cleanups can stabilize :-)
> 

Makes sense. I guess I got ahead of myself when extending the original v1 of this patch series from only dealing with the CRS problem to "let's fix the world"
:-)  I will reorder my patches a bit and post them as two separate series, so that the CRS-related stuff can be pushed earlier and on its own while the rest
stabilizes.

> I would also mark that for stable.



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  reply	other threads:[~2020-03-06 18:07 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-03 13:28 [PATCH v3 00/17] Improve PCI device post-reset readiness polling Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 01/17] PCI: Fall back to slot/bus reset if softer methods timeout Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 02/17] PCI: Remove unused PCI_PM_BUS_WAIT Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 03/17] PCI: Use pci_bridge_wait_for_secondary_bus after SBR Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 04/17] PCI: Do not override delay for D0->D3hot transition Stanislav Spassov
2020-03-03 18:57   ` Rafael J. Wysocki
2020-03-07 10:58     ` Spassov, Stanislav
2020-03-03 13:28 ` [PATCH v3 05/17] PCI: Fix handling of _DSM 8 (avoiding reset delays) Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 06/17] PCI: Fix us->ms conversion in pci_acpi_optimize_delay Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 07/17] PCI: Clean up and document PM/reset delays Stanislav Spassov
2020-03-03 19:03   ` Rafael J. Wysocki
2020-03-07 11:30     ` Spassov, Stanislav
2020-03-03 13:28 ` [PATCH v3 08/17] PCI: Add more delay overrides to struct pci_dev Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 09/17] PCI: Generalize pci_bus_max_d3cold_delay to pci_bus_max_delay Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 10/17] PCI: Use correct delay in pci_bridge_wait_for_secondary_bus Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 11/17] PCI: Refactor pci_dev_wait to remove timeout parameter Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 12/17] PCI: Refactor pci_dev_wait to take pci_init_event Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 13/17] PCI: Cache CRS Software Visibiliy in struct pci_dev Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 14/17] PCI: Introduce per-device reset_ready_poll override Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 15/17] PCI: Refactor polling loop out of pci_dev_wait Stanislav Spassov
2020-03-03 13:28 ` [PATCH v3 16/17] PCI: Add CRS handling to pci_dev_wait() Stanislav Spassov
2020-03-05 17:56   ` Raj, Ashok
2020-03-06 18:07     ` Spassov, Stanislav [this message]
2020-03-03 13:28 ` [PATCH v3 17/17] PCI: Lower PCIE_RESET_READY_POLL_MS from 1m to 1s Stanislav Spassov

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