[PATCH] PCI: stop spamming info in quirk_nvidia_hda

[PATCH] PCI: stop spamming info in quirk_nvidia_hda

[Karol Herbst]

Users kept complaining about those messages and it's a little spammy on
prime systems so turn it into a debug print.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: linux-pci@vger.kernel.org
Cc: nouveau@lists.freedesktop.org
Fixes: b516ea586d71 ("PCI: Enable NVIDIA HDA controllers")
Signed-off-by: Karol Herbst <kherbst@redhat.com>
---
 drivers/pci/quirks.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 44cab813bf951..b10c77bbe4716 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5549,7 +5549,7 @@ static void quirk_nvidia_hda(struct pci_dev *gpu)
 	if (val & BIT(25))
 		return;
 
-	pci_info(gpu, "Enabling HDA controller\n");
+	pci_dbg(gpu, "Enabling HDA controller\n");
 	pci_write_config_dword(gpu, 0x488, val | BIT(25));
 
 	/* The GPU becomes a multi-function device when the HDA is enabled */
-- 
2.39.2

Re: [PATCH] PCI: stop spamming info in quirk_nvidia_hda

[Lukas Wunner]

On Thu, Mar 16, 2023 at 03:31:22PM +0100, Karol Herbst wrote:
> Users kept complaining about those messages and it's a little spammy on
> prime systems so turn it into a debug print.
> 
> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Lukas Wunner <lukas@wunner.de>
> Cc: linux-pci@vger.kernel.org
> Cc: nouveau@lists.freedesktop.org
> Fixes: b516ea586d71 ("PCI: Enable NVIDIA HDA controllers")
> Signed-off-by: Karol Herbst <kherbst@redhat.com>

Could you provide Link: tags to bugzillas or mailing list messages
of those complaints so that the sentence sounds a little less like
hand-waving?

The point of the message is that if users see adverse effects as a
result of exposing the hidden HDA controller, they get a hint in
dmesg as to the cause.  Hopefully the existence of such adverse
effects can be ruled out by now.

Thanks,

Lukas

> ---
>  drivers/pci/quirks.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 44cab813bf951..b10c77bbe4716 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -5549,7 +5549,7 @@ static void quirk_nvidia_hda(struct pci_dev *gpu)
>  	if (val & BIT(25))
>  		return;
>  
> -	pci_info(gpu, "Enabling HDA controller\n");
> +	pci_dbg(gpu, "Enabling HDA controller\n");
>  	pci_write_config_dword(gpu, 0x488, val | BIT(25));
>  
>  	/* The GPU becomes a multi-function device when the HDA is enabled */
> -- 
> 2.39.2

Re: [PATCH] PCI: stop spamming info in quirk_nvidia_hda

[Bjorn Helgaas]

On Thu, Mar 16, 2023 at 03:31:22PM +0100, Karol Herbst wrote:
> Users kept complaining about those messages and it's a little spammy on
> prime systems so turn it into a debug print.

What is a "prime system"?

I'm a little surprised that users would really care about the message.
But I do see comments like these:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1836308/comments/15
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2002206
that suggest the message happens frequently, maybe if we're resuming
the controller after runtime suspend?

Maybe this should be a pci_info_once() sort of thing?  I think there's
some value in knowing that we're changing the BIOS configuration
outside the purview of a driver, since I assume BIOS had some reason
for hiding the HDA controller.

> Cc: Bjorn Helgaas <bhelgaas@google.com>
> Cc: Lukas Wunner <lukas@wunner.de>
> Cc: linux-pci@vger.kernel.org
> Cc: nouveau@lists.freedesktop.org
> Fixes: b516ea586d71 ("PCI: Enable NVIDIA HDA controllers")
> Signed-off-by: Karol Herbst <kherbst@redhat.com>
> ---
>  drivers/pci/quirks.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 44cab813bf951..b10c77bbe4716 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -5549,7 +5549,7 @@ static void quirk_nvidia_hda(struct pci_dev *gpu)
>  	if (val & BIT(25))
>  		return;
>  
> -	pci_info(gpu, "Enabling HDA controller\n");
> +	pci_dbg(gpu, "Enabling HDA controller\n");
>  	pci_write_config_dword(gpu, 0x488, val | BIT(25));
>  
>  	/* The GPU becomes a multi-function device when the HDA is enabled */
> -- 
> 2.39.2
> 

Re: [PATCH] PCI: stop spamming info in quirk_nvidia_hda

[Karol Herbst]

On Thu, Mar 16, 2023 at 8:57 PM Bjorn Helgaas <helgaas@kernel.org> wrote:
>
> On Thu, Mar 16, 2023 at 03:31:22PM +0100, Karol Herbst wrote:
> > Users kept complaining about those messages and it's a little spammy on
> > prime systems so turn it into a debug print.
>
> What is a "prime system"?
>

Laptops with a iGPU + Nvidia Setup. That tech is usually marketed as
"Nvidia Optimus" and people in the open source world made "prime" out
of that, mostly in the context of "prime offloading".

> I'm a little surprised that users would really care about the message.
> But I do see comments like these:
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1836308/comments/15
> https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2002206
> that suggest the message happens frequently, maybe if we're resuming
> the controller after runtime suspend?
>

Yes, that happens every time the discrete Nvidia GPU gets runtime resumed.

> Maybe this should be a pci_info_once() sort of thing?  I think there's
> some value in knowing that we're changing the BIOS configuration
> outside the purview of a driver, since I assume BIOS had some reason
> for hiding the HDA controller.
>

fair point. Most of the bugs happen on the first runtime resume
already, so if that one is good, it's unlikely the system will hit a
bug later on.

> > Cc: Bjorn Helgaas <bhelgaas@google.com>
> > Cc: Lukas Wunner <lukas@wunner.de>
> > Cc: linux-pci@vger.kernel.org
> > Cc: nouveau@lists.freedesktop.org
> > Fixes: b516ea586d71 ("PCI: Enable NVIDIA HDA controllers")
> > Signed-off-by: Karol Herbst <kherbst@redhat.com>
> > ---
> >  drivers/pci/quirks.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> > index 44cab813bf951..b10c77bbe4716 100644
> > --- a/drivers/pci/quirks.c
> > +++ b/drivers/pci/quirks.c
> > @@ -5549,7 +5549,7 @@ static void quirk_nvidia_hda(struct pci_dev *gpu)
> >       if (val & BIT(25))
> >               return;
> >
> > -     pci_info(gpu, "Enabling HDA controller\n");
> > +     pci_dbg(gpu, "Enabling HDA controller\n");
> >       pci_write_config_dword(gpu, 0x488, val | BIT(25));
> >
> >       /* The GPU becomes a multi-function device when the HDA is enabled */
> > --
> > 2.39.2
> >
>