[PATCH v2 0/2] add hotplug depedency info

[PATCH v2 0/2] add hotplug depedency info

[Albert Zhou]

v1->v2: I added comments that PCIe cards with USB4 or Thunderbolt also
require the hotplug feature. I also added the "default y if USB4" line
to the relevant config options, as suggested by Lukas Wunner.

Albert Zhou (2):
  pci: hotplug: add dependency info to Kconfig
  pci: pcie: add dependency info to Kconfig

 drivers/pci/hotplug/Kconfig | 4 +++-
 drivers/pci/pcie/Kconfig    | 5 +++--
 2 files changed, 6 insertions(+), 3 deletions(-)


base-commit: fef7fd48922d11b22620e19f9c9101647bfe943d
-- 
2.34.1

[PATCH v2 1/2] pci: hotplug: add dependency info to Kconfig

[Albert Zhou]

Thunderbolt and USB4 PCI cards require the hotplug feature. This is now
recorded in the help message for HOTPLUG_PCI. Further, HOTPLUG_PCI is
defaulted to Y if USB4 is selected.

Signed-off-by: Albert Zhou <albert.zhou.50@gmail.com>
---
 drivers/pci/hotplug/Kconfig | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig
index 840a84bb5ee2..06cc373834f5 100644
--- a/drivers/pci/hotplug/Kconfig
+++ b/drivers/pci/hotplug/Kconfig
@@ -6,10 +6,12 @@
 menuconfig HOTPLUG_PCI
 	bool "Support for PCI Hotplug"
 	depends on PCI && SYSFS
+	default y if USB4
 	help
 	  Say Y here if you have a motherboard with a PCI Hotplug controller.
 	  This allows you to add and remove PCI cards while the machine is
-	  powered up and running.
+	  powered up and running. Thunderbolt and USB4 PCI cards require
+	  Hotplug.
 
 	  When in doubt, say N.
 
-- 
2.34.1

[PATCH v2 2/2] pci: pcie: add dependency info to Kconfig

[Albert Zhou]

Thunderbolt and USB4 PCIe cards require the hotplug feature. This is now
recorded in the help message for HOTPLUG_PCI_PCIE. Further, PCIEPORTBUS
and HOTPLUG_PCI_PCIE are defaulted to Y if USB4 is selected.

Signed-off-by: Albert Zhou <albert.zhou.50@gmail.com>
---
 drivers/pci/pcie/Kconfig | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 788ac8df3f9d..6c54a4512e2b 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -4,20 +4,21 @@
 #
 config PCIEPORTBUS
 	bool "PCI Express Port Bus support"
+	default y if USB4
 	help
 	  This enables PCI Express Port Bus support. Users can then enable
 	  support for Native Hot-Plug, Advanced Error Reporting, Power
 	  Management Events, and Downstream Port Containment.
-
 #
 # Include service Kconfig here
 #
 config HOTPLUG_PCI_PCIE
 	bool "PCI Express Hotplug driver"
 	depends on HOTPLUG_PCI && PCIEPORTBUS
+	default y if USB4
 	help
 	  Say Y here if you have a motherboard that supports PCI Express Native
-	  Hotplug
+	  Hotplug. Thunderbolt and USB4 PCIe cards require Hotplug.
 
 	  When in doubt, say N.
 
-- 
2.34.1

Re: [PATCH v2 1/2] pci: hotplug: add dependency info to Kconfig

[Mika Westerberg]

On Sun, Nov 13, 2022 at 10:28:10PM +1100, Albert Zhou wrote:
> Thunderbolt and USB4 PCI cards require the hotplug feature. This is now
> recorded in the help message for HOTPLUG_PCI. Further, HOTPLUG_PCI is
> defaulted to Y if USB4 is selected.
> 
> Signed-off-by: Albert Zhou <albert.zhou.50@gmail.com>
> ---
>  drivers/pci/hotplug/Kconfig | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig
> index 840a84bb5ee2..06cc373834f5 100644
> --- a/drivers/pci/hotplug/Kconfig
> +++ b/drivers/pci/hotplug/Kconfig
> @@ -6,10 +6,12 @@
>  menuconfig HOTPLUG_PCI
>  	bool "Support for PCI Hotplug"
>  	depends on PCI && SYSFS
> +	default y if USB4
>  	help
>  	  Say Y here if you have a motherboard with a PCI Hotplug controller.
>  	  This allows you to add and remove PCI cards while the machine is
> -	  powered up and running.
> +	  powered up and running. Thunderbolt and USB4 PCI cards require
> +	  Hotplug.

I would not say they "require" this. PCIe is completely optional in USB4
systems and it is perfectly fine to have host controllers or
add-in-cards that don't have a single PCIe adapter.

Not objeting the patch, though. For Linux I guess it makes sense to have
this like what you are suggesting. Just perhaps changing the wordirng
;-)

Re: [PATCH v2 1/2] pci: hotplug: add dependency info to Kconfig

[Albert Zhou]

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On 14/11/22 21:37, Mika Westerberg wrote:
>> +	default y if USB4
>>   	help
>>   	  Say Y here if you have a motherboard with a PCI Hotplug controller.
>>   	  This allows you to add and remove PCI cards while the machine is
>> -	  powered up and running.
>> +	  powered up and running. Thunderbolt and USB4 PCI cards require
>> +	  Hotplug.
> I would not say they "require" this. PCIe is completely optional in USB4
> systems and it is perfectly fine to have host controllers or
> add-in-cards that don't have a single PCIe adapter.
> 
> Not objeting the patch, though. For Linux I guess it makes sense to have
> this like what you are suggesting. Just perhaps changing the wordirng
> 😉

How about “Thunderbolt and USB4 use Hotplug”

Do you agree with the “default y if USB4” for PCIEPORTBUS, HOTPLUG_PCI_PCIE, HOTPLUG_PCI.

 From Albert Zhou

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Re: [PATCH v2 1/2] pci: hotplug: add dependency info to Kconfig

[Mika Westerberg]

Hi,

On Tue, Nov 15, 2022 at 12:38:11PM +1100, Albert Zhou wrote:
> On 14/11/22 21:37, Mika Westerberg wrote:
> > > +	default y if USB4
> > >   	help
> > >   	  Say Y here if you have a motherboard with a PCI Hotplug controller.
> > >   	  This allows you to add and remove PCI cards while the machine is
> > > -	  powered up and running.
> > > +	  powered up and running. Thunderbolt and USB4 PCI cards require
> > > +	  Hotplug.
> > I would not say they "require" this. PCIe is completely optional in USB4
> > systems and it is perfectly fine to have host controllers or
> > add-in-cards that don't have a single PCIe adapter.
> > 
> > Not objeting the patch, though. For Linux I guess it makes sense to have
> > this like what you are suggesting. Just perhaps changing the wordirng
> > 😉
> 
> How about “Thunderbolt and USB4 use Hotplug”

Or

"Thunderbolt/USB4 PCIe tunneling needs Native PCIe Hotplug to be enabled"

> Do you agree with the “default y if USB4” for PCIEPORTBUS, HOTPLUG_PCI_PCIE, HOTPLUG_PCI.

Yes, I think for Linux perspective it makes sense to have them enabled
by default.