Re: [PATCH v5 2/3] PCI: Move pci_bus_speed2lnkctl2() to public header

[Hans Zhang <18255117159@163.com>]

On 4/7/26 20:26, Ilpo Järvinen wrote:
> On Tue, 7 Apr 2026, Hans Zhang wrote:
> 
>>
>>
>> On 4/7/26 16:11, Ilpo Järvinen wrote:
>>> On Mon, 6 Apr 2026, Hans Zhang wrote:
>>>
>>>> Move the static array-based pci_bus_speed2lnkctl2() function from
>>>> bwctrl.c to pci.h as a public inline function.
>>>>
>>>> This provides efficient O(1) speed-to-LNKCTL2 value conversion using
>>>> static array lookup, maintaining optimal performance while enabling
>>>> code reuse by other PCIe drivers.
>>>>
>>>> Signed-off-by: Hans Zhang <18255117159@163.com>
>>>> ---
>>>>    drivers/pci/pci.h         | 17 +++++++++++++++++
>>>>    drivers/pci/pcie/bwctrl.c | 17 -----------------
>>>>    2 files changed, 17 insertions(+), 17 deletions(-)
>>>>
>>>> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
>>>> index f0a082bfd6f1..db91878a86ac 100644
>>>> --- a/drivers/pci/pci.h
>>>> +++ b/drivers/pci/pci.h
>>>> @@ -611,6 +611,23 @@ static inline bool pcie_valid_speed(enum
>>>> pci_bus_speed speed)
>>>>    	return (speed >= PCIE_SPEED_2_5GT) && (speed <= PCIE_SPEED_64_0GT);
>>>>    }
>>>>    +static inline u16 pci_bus_speed2lnkctl2(enum pci_bus_speed speed)
>>>> +{
>>>> +	static const u8 speed_conv[] = {
>>>> +		[PCIE_SPEED_2_5GT] = PCI_EXP_LNKCTL2_TLS_2_5GT,
>>>> +		[PCIE_SPEED_5_0GT] = PCI_EXP_LNKCTL2_TLS_5_0GT,
>>>> +		[PCIE_SPEED_8_0GT] = PCI_EXP_LNKCTL2_TLS_8_0GT,
>>>> +		[PCIE_SPEED_16_0GT] = PCI_EXP_LNKCTL2_TLS_16_0GT,
>>>> +		[PCIE_SPEED_32_0GT] = PCI_EXP_LNKCTL2_TLS_32_0GT,
>>>> +		[PCIE_SPEED_64_0GT] = PCI_EXP_LNKCTL2_TLS_64_0GT,
>>>> +	};
>>>> +
>>>> +	if (WARN_ON_ONCE(!pcie_valid_speed(speed)))
>>>
>>> drivers/pci/pci.h doesn't seem to have include for WARN_ON_ONCE() so you
>>> should add it.
>>
>> Hi Ilpo,
>>
>> In the file "drivers/pci/pcie/bwctrl.c", there is no reference to the header
>> file of WARN_ON_ONCE(). It seems that no error was reported. I think it might
>> be that some other header files have indirectly referenced the header file of
>> WARN_ON_ONCE(). However, when I compiled it locally, no errors were reported.
> 
> Hi,
> 
> Apparently it was missing from there as well.
> 
> It might build now (I don't actually even doubt that), but that depends
> on the includes in every file including drivers/pci/pci.h. We should not
> depend on that as it is fragile but ensure a header is self-sufficient
> when it comes to includes necessary for it.

Hi Ilpo,

OK, I see.


> 
>> I think if we want to add a header file, it should be #include
>> <asm-generic/bug.h> ?
> 
> Yes
> 
> #include <asm/bug.h>

Thank you. Will add.

Best regards,
Hans
>