Re: [PATCH] serial: parisc: GSC: fix build when PCI_LBA is not set

[Randy Dunlap]

Hi Helge,

On 2/14/22 04:24, Helge Deller wrote:
> On 2/14/22 13:05, Helge Deller wrote:
>> On 2/14/22 01:15, Randy Dunlap wrote:
>>> Hi,
>>>
>>> On 2/13/22 14:15, Helge Deller wrote:
>>>> On 2/13/22 22:07, Randy Dunlap wrote:
>>>>>
>>>>>
>>>>> On 2/13/22 12:35, Helge Deller wrote:
>>>>>> Hi Randy,
>>>>>>
>>>>>> On 2/13/22 20:39, Randy Dunlap wrote:
>>>>>>> There is a build error when using a kernel .config file from
>>>>>>> 'kernel test robot' for a different build problem:
>>>>>>>
>>>>>>> hppa64-linux-ld: drivers/tty/serial/8250/8250_gsc.o: in function `.LC3':
>>>>>>> (.data.rel.ro+0x18): undefined reference to `iosapic_serial_irq'
>>>>>>>
>>>>>>> when:
>>>>>>>   CONFIG_GSC=y
>>>>>>>   CONFIG_SERIO_GSCPS2=y
>>>>>>>   CONFIG_SERIAL_8250_GSC=y
>>>>>>>   CONFIG_PCI is not set
>>>>>>>     and hence PCI_LBA is not set.
>>>>>>>   IOSAPIC depends on PCI_LBA, so IOSAPIC is not set/enabled.
>>>>>>>
>>>>>>> Making SERIAL_8250_GSC depend on PCI_LBA prevents the build error.
>>>>>>
>>>>>> It maybe makes the build error go away, but ...
>>>>>>
>>>>>>> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>>>>>>> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>>>>>>> Cc: "James E.J. Bottomley" <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
>>>>>>> Cc: Helge Deller <deller@xxxxxx>
>>>>>>> Cc: linux-parisc@xxxxxxxxxxxxxxx
>>>>>>> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>>>>>>> Cc: linux-serial@xxxxxxxxxxxxxxx
>>>>>>> Cc: Jiri Slaby <jirislaby@xxxxxxxxxx>
>>>>>>> Cc: Johan Hovold <johan@xxxxxxxxxx>
>>>>>>> ---
>>>>>>>  drivers/tty/serial/8250/Kconfig |    2 +-
>>>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>>
>>>>>>> --- linux-next-20220211.orig/drivers/tty/serial/8250/Kconfig
>>>>>>> +++ linux-next-20220211/drivers/tty/serial/8250/Kconfig
>>>>>>> @@ -118,7 +118,7 @@ config SERIAL_8250_CONSOLE
>>>>>>>
>>>>>>>  config SERIAL_8250_GSC
>>>>>>>  	tristate
>>>>>>> -	depends on SERIAL_8250 && GSC
>>>>>>> +	depends on SERIAL_8250 && GSC && PCI_LBA
>>>>>>>  	default SERIAL_8250
>>>>>>
>>>>>> The serial device is on the GSC bus, so if you make it
>>>>>> dependend on the PCI bus it will not be useable on machines
>>>>>> which only have a GSC bus...
>>>>>>
>>>>>> We need another patch.
>>>>>> Do you have a link to the build error?
>>>>>
>>>>>
>>>>> No, it's from the other build error that you just replied to,
>>>>> where the incorrect compiler was used.
>>>>>
>>>>> I'll recheck it and reconsider what to do, if anything.
>>>>
>>>> Ok, thank you!
>>>
>>> I dunno what to do. This:
>>>
>>> #ifdef CONFIG_64BIT
>>> 	if (!dev->irq && (dev->id.sversion == 0xad))
>>> 		dev->irq = iosapic_serial_irq(dev);
>>> #endif
>>>
>>> makes it look like 64BIT requires IOSAPIC (hence PCI_LBA).
>>
>> Although I think all 64bit machines have a PCI bus, the better
>> fix is that the driver should only call iosapic_serial_irq(dev)
>> if CONFIG_IOSAPIC is set. This patch fixes the build:
>>
>> -#ifdef CONFIG_64BIT
>> +#ifdef CONFIG_IOSAPIC
>>         if (!dev->irq && (dev->id.sversion == 0xad))
>>                 dev->irq = iosapic_serial_irq(dev);
>>  #endif
> 
> That was not fully correct.
> It needs to be:
> 
> #if defined(CONFIG_64BIT) && defined(CONFIG_IOSAPIC)
> 
> Otherwise you'll get an undefined reference in the 32-bit build.

Sure, I can send such a patch.
I would have used a bigger hammer and done something like

	depends on IOSAPIC if 64BIT


Just for info, how would dev->irq be set for CONFIG_64BIT
when CONFIG_IOSAPIC is not set?


thanks.
-- 
~Randy