From: "Kuppuswamy, Sathyanarayanan" <sathyanarayanan.kuppuswamy@linux.intel.com>
To: Bjorn Helgaas <helgaas@kernel.org>
Cc: bhelgaas@google.com, linux-pci@vger.kernel.org,
linux-kernel@vger.kernel.org, ashok.raj@intel.com,
knsathya@kernel.org
Subject: Re: [PATCH v11 2/5] ACPI/PCI: Ignore _OSC negotiation result if pcie_ports_native is set.
Date: Wed, 25 Nov 2020 16:58:28 -0800 [thread overview]
Message-ID: <59eaec1e-d857-9122-8658-29ec3b62294e@linux.intel.com> (raw)
In-Reply-To: <20201125202810.GA674732@bjorn-Precision-5520>
On 11/25/20 12:28 PM, Bjorn Helgaas wrote:
> On Mon, Oct 26, 2020 at 07:57:05PM -0700, Kuppuswamy Sathyanarayanan wrote:
>> pcie_ports_native is set only if user requests native handling
>> of PCIe capabilities via pcie_port_setup command line option.
>> User input takes precedence over _OSC based control negotiation
>> result. So consider the _OSC negotiated result only if
>> pcie_ports_native is unset.
>>
>> Also, since struct pci_host_bridge ->native_* members caches the
>> ownership status of various PCIe capabilities, use them instead
>> of distributed checks for pcie_ports_native.
>
>> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
>> index 50a9522ab07d..ccd5e0ce5605 100644
>> --- a/drivers/pci/pcie/portdrv_core.c
>> +++ b/drivers/pci/pcie/portdrv_core.c
>> @@ -208,8 +208,7 @@ static int get_port_device_capability(struct pci_dev *dev)
>> struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
>> int services = 0;
>>
>> - if (dev->is_hotplug_bridge &&
>> - (pcie_ports_native || host->native_pcie_hotplug)) {
>> + if (dev->is_hotplug_bridge && host->native_pcie_hotplug) {
>
> This is a nit, but I think this and similar checks should be reordered
> so we do the most generic test first, i.e.,
>
> if (host->native_pcie_hotplug && dev->is_hotplug_bridge)
ok. I can add this fix on top of your update.
>
> Logically there's no point in looking at the device things if we
> don't have native control.
>
>> services |= PCIE_PORT_SERVICE_HP;
>>
>> /*
>> @@ -221,8 +220,7 @@ static int get_port_device_capability(struct pci_dev *dev)
>> }
>>
>> #ifdef CONFIG_PCIEAER
>> - if (dev->aer_cap && pci_aer_available() &&
>> - (pcie_ports_native || host->native_aer)) {
>> + if (dev->aer_cap && pci_aer_available() && host->native_aer) {
>
> Can't we clear host->native_aer when pci_aer_available() returns
> false? I'd like to have all the checks about whether we have native
> control to be in one place instead of being scattered. Something like
> this above:
>
> OSC_OWNER(ctrl, OSC_PCI_EXPRESS_AER_CONTROL, host_bridge->native_aer);
> if (!pci_aer_available())
> host_bridge->native_aer = 0;
>
> So this test would become:
>
> if (host->native_aer && dev->aer_cap)
We already use it in pci_root.c to confirm AER availability before
we request control over it via _OSC. So if pci_aer_available() is false
OSC_*AER_CONTROL bit in ctrl_set will be left zero (which means
->native_aer will also be zero).
490 if (pci_aer_available())
491 control |= OSC_PCI_EXPRESS_AER_CONTROL;
So, may we don't need pci_aer_available() check here.
>
>> services |= PCIE_PORT_SERVICE_AER;
>>
>> /*
>> @@ -238,8 +236,7 @@ static int get_port_device_capability(struct pci_dev *dev)
>> * Event Collectors can also generate PMEs, but we don't handle
>> * those yet.
>> */
>> - if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT &&
>> - (pcie_ports_native || host->native_pme)) {
>> + if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT && host->native_pme) {
>> services |= PCIE_PORT_SERVICE_PME;
>
> Also here:
>
> if (host->native_pme && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT)
>
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
next prev parent reply other threads:[~2020-11-26 0:58 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-27 2:57 [PATCH v11 0/5] Simplify PCIe native ownership detection logic Kuppuswamy Sathyanarayanan
2020-10-27 2:57 ` [PATCH v11 1/5] PCI: Conditionally initialize host bridge native_* members Kuppuswamy Sathyanarayanan
2020-10-28 6:09 ` Ethan Zhao
2020-10-28 17:14 ` Kuppuswamy, Sathyanarayanan
2020-10-27 2:57 ` [PATCH v11 2/5] ACPI/PCI: Ignore _OSC negotiation result if pcie_ports_native is set Kuppuswamy Sathyanarayanan
2020-11-25 20:12 ` Bjorn Helgaas
2020-11-25 22:21 ` Kuppuswamy, Sathyanarayanan
2020-11-25 22:25 ` Bjorn Helgaas
2020-11-25 22:38 ` Kuppuswamy, Sathyanarayanan
2020-11-25 20:28 ` Bjorn Helgaas
2020-11-26 0:58 ` Kuppuswamy, Sathyanarayanan [this message]
2020-10-27 2:57 ` [PATCH v11 3/5] ACPI/PCI: Ignore _OSC DPC negotiation result if pcie_ports_dpc_native " Kuppuswamy Sathyanarayanan
2020-11-25 20:50 ` Bjorn Helgaas
2020-10-27 2:57 ` [PATCH v11 4/5] PCI/portdrv: Remove redundant pci_aer_available() check in DPC enable logic Kuppuswamy Sathyanarayanan
2020-10-28 6:00 ` Ethan Zhao
2020-10-28 17:13 ` Kuppuswamy, Sathyanarayanan
2020-11-02 9:59 ` Ethan Zhao
2020-10-27 2:57 ` [PATCH v11 5/5] PCI/DPC: Move AER/DPC dependency checks out of DPC driver Kuppuswamy Sathyanarayanan
2020-11-13 21:59 ` [PATCH v11 0/5] Simplify PCIe native ownership detection logic Kuppuswamy, Sathyanarayanan
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