Messages in this thread | | | Subject | Re: [RFC PATCH 5/8] qaic: Implement data path | From | Jeffrey Hugo <> | Date | Thu, 14 May 2020 10:45:50 -0600 |
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On 5/14/2020 10:37 AM, Greg KH wrote: > On Thu, May 14, 2020 at 10:12:03AM -0600, Jeffrey Hugo wrote: >> On 5/14/2020 9:56 AM, Greg KH wrote: >>> On Thu, May 14, 2020 at 09:06:53AM -0600, Jeffrey Hugo wrote: >>>> On 5/14/2020 8:14 AM, Greg KH wrote: >>>>> On Thu, May 14, 2020 at 08:07:43AM -0600, Jeffrey Hugo wrote: >>>>>> +struct qaic_execute { >>>>>> + __u16 ver; /* struct version, must be 1 */ >>>>> >>>>> No need for structures to be versioned. If you change something, then >>>>> add a new ioctl if you really needed it. >>>> >>>> Huh. We had thought the botching ioctls document advised having a version, >>>> but as I double check that document, it infact does not. >>>> >>>> Will remove. >>> >>> Thanks, you can also remove the "reserved" variables as well as those >>> will not be needed either. >> >> Are you sure? >> >> Documentation/process/botching-up-ioctls.rst >> Starting at Line 38: >> >> "Pad the entire struct to a multiple of 64-bits if the structure contains >> 64-bit types - the structure size will otherwise differ on 32-bit versus >> 64-bit. Having a different structure size hurts when passing arrays of >> structures to the kernel, or if the kernel checks the structure size, which >> e.g. the drm core does." >> >> The "reserved" variables seem to be in line with that. > > Padding is fine to use, but don't use that as a "I'm reserving this to > use it for later" type of thing which is how I read the structure > definitions. I might be totally wrong, but you should be explicit here.
Ok, I think I see your point. I'll change them to be more explicit as padding.
-- Jeffrey Hugo Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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