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

[Hans Zhang <18255117159@163.com>]

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.

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

Best regards,
Hans

>