Thomas Zimmermann <tzimmermann@xxxxxxx> wrote: > Am 19.04.23 um 06:48 schrieb Pierre Asselin: >> >> v2 fixes the warnings from a max3() macro with arguments of different >> types; split the bits_per_pixel assignment to avoid uglyfing the code >> with too many typecasts. > > What exactly was that warning? A friendly note from a robot; make W=1 sysfb_simplefb.o . https://lore.kernel.org/dri-devel/20230418183325.2327-1-pa@xxxxxxxxx/T/#m38e859354329ab9f756da91e99b546e3b140fa91 > I liked the all-in-one assignment of the original patch. So I'd rather > go back to v1 and copy si->lfb_depth to the correct type, like this: > > u32 depth = si->lfb_depth; > bits_per_pixel = max3(max3(colors), > rsvd, > depth); Would that work? If I understand correctly max3() checks that all args have the same type. {red,green,blue,rsvd}.{size,pos} are all u8 while lfb_depth is u16. The best I can do is bits_per_pixel = max3((u16)max3(si->red_size + si->red_pos, si->green_size + si->green_pos, si->blue_size + si->blue_pos), (u16)(si->rsvd_size + si->rsvd_pos), si->lfb_depth); That compiles quietly with W=1 but those two casts are ugly. If I do that, would K&R-on-parentheses read better ? bits_per_pixel = max3( (u16)max3( si->red_size + si->red_pos, si->green_size + si->green_pos, si->blue_size + si->blue_pos ), (u16)(si->rsvd_size + si->rsvd_pos), si->lfb_depth ); I think it's clearer, but not kernel style and still ugly. > Or, if you want to get fancy, you could add max3_t() to <linux/minmax.h> > > #define max3_t(type, x, y, z) max_t(type, max_t(type, x, y), z) > > and do > > bits_per_pixel = max3_t(u32, > max3(colors), > rsvd, > si->lfb_depth) > > You could also add a max4_t(type, x, y, z, w) to <linux/minmax.h> and > compare all values with max4_t(). That would be a two-patch series. I'd rather keep it to the strict minimum that fixes the regression. (You trust me to even *look* at a kernel header and not break it ? Dangerous assumption!) I'm new at this. Two months ago I didn't know what to type a the command line after "git". Incidentally, should I send v3 as a new email or reply to the chain? --PA
