Re: [PATCH] xen: Remove trigraphs from comments

[Jan Beulich <jbeulich@xxxxxxxx>]

On 06.12.2022 14:05, Michal Orzel wrote:
> On 06/12/2022 13:42, Jan Beulich wrote:
>> On 06.12.2022 11:59, Michal Orzel wrote:
>>> --- a/xen/include/xen/pci_regs.h
>>> +++ b/xen/include/xen/pci_regs.h
>>> @@ -246,13 +246,13 @@
>>>  #define  PCI_PM_CTRL_STATE_MASK      0x0003  /* Current power state (D0 to 
>>> D3) */
>>>  #define  PCI_PM_CTRL_NO_SOFT_RESET   0x0008  /* No reset for D3hot->D0 */
>>>  #define  PCI_PM_CTRL_PME_ENABLE      0x0100  /* PME pin enable */
>>> -#define  PCI_PM_CTRL_DATA_SEL_MASK   0x1e00  /* Data select (??) */
>>> -#define  PCI_PM_CTRL_DATA_SCALE_MASK 0x6000  /* Data scale (??) */
>>> +#define  PCI_PM_CTRL_DATA_SEL_MASK   0x1e00  /* Data select (?) */
>>> +#define  PCI_PM_CTRL_DATA_SCALE_MASK 0x6000  /* Data scale (?) */
>>>  #define  PCI_PM_CTRL_PME_STATUS      0x8000  /* PME pin status */
>>> -#define PCI_PM_PPB_EXTENSIONS        6       /* PPB support extensions 
>>> (??) */
>>> -#define  PCI_PM_PPB_B2_B3    0x40    /* Stop clock when in D3hot (??) */
>>> -#define  PCI_PM_BPCC_ENABLE  0x80    /* Bus power/clock control enable 
>>> (??) */
>>> -#define PCI_PM_DATA_REGISTER 7       /* (??) */
>>> +#define PCI_PM_PPB_EXTENSIONS        6       /* PPB support extensions (?) 
>>> */
>>> +#define  PCI_PM_PPB_B2_B3    0x40    /* Stop clock when in D3hot (?) */
>>> +#define  PCI_PM_BPCC_ENABLE  0x80    /* Bus power/clock control enable (?) 
>>> */
>>> +#define PCI_PM_DATA_REGISTER 7       /* (?) */
>>>  #define PCI_PM_SIZEOF                8
>>
>> We've inherited all of these from Linux, and I notice Linux still has it
>> this same way. Ideally Linux would change first, but I'd be okay with a
>> sentence added to the description clarifying that we knowingly accept
>> the divergence.
> This file already diverged and we are not in sync with Linux as well.

Of course - that's the case for the majority of files we've taken from
somewhere. But a Linux patch dropping the (??) parts of the comment
(perhaps once whoever had put them there convinced themselves that the
names of the constants and/or the comments are valid / applicable)
would then no longer apply cleanly if we wanted to carry it over.
Hence my request for amending the description.

> Also there is no functional change being made by this patch so it is ok
> to change Xen and not Linux in this case (which has quite a lot of trigraphs 
> all over the place).

Based on what criteria are you saying this is ok (unconditionally)?

Jan