Re: [PATCH] PCI/VPD: Silence warning if optional VPD PROM is missing

[Heiner Kallweit <hkallweit1@gmail.com>]

On 30.03.2021 21:56, Bjorn Helgaas wrote:
> On Sun, Mar 07, 2021 at 10:34:25PM +0100, Heiner Kallweit wrote:
>> On 07.03.2021 19:27, Krzysztof Wilczyński wrote:
>>> Hi Heiner,
>>>
>>>> Realtek RTL8169/8168/8125 NIC families indicate VPD capability and an
>>>> optional VPD EEPROM can be connected via I2C/SPI. However I haven't
>>>> seen any card or system with such a VPD EEPROM yet. The missing EEPROM
>>>> causes the following warning whenever e.g. lscpi -vv is executed.
>>>>
>>>> invalid short VPD tag 00 at offset 01
>>>>
>>>> The warning confuses users, I think we should handle the situation more
>>>> gentle. Therefore, if first VPD byte is read as 0x00, assume a missing
>>>> optional VPD PROM as and silently set the VPD length to 0.
>>> [...]
>>>
>>> True.  I saw people on different forum and IRC asking for clarification
>>> assuming their NIC broke, or that something is wrong, so this would
>>> indeed save them some worry, nice!
>>>
>>> Having said that, I also saw this particular warning showing up for some
>>> storage controllers (often some SAS cards), so a question here: would it
>>> warrant adding a pci_dbg() with an appropriate message rather than just
>>> returning 0?  I wonder if this might be useful for someone who is trying
>>> to troubleshoot and/or debug some issues with their device.
>>>
>>> What do you think?
>>>
>> I don't have a strong opinion here, but yes, that's something we could do.
> 
> How about if we just downgrade the pci_warn() to a pci_info()?
> 
pci_info() would still expose a quite cryptic message to users and leave
them with the question whether something is wrong. If in case of VPD tag 00
a message is desired, I'd say it should be rephrased to something like:
"VPD tag 00 at offset 01, assuming missing optional VPD EPROM"