On Thu, Jul 23, 2020 at 11:09:40AM +0200, Arnd Bergmann wrote: > On Thu, Jul 23, 2020 at 9:39 AM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote: > > > > do-while is a preferred way for complex macros because of safety > > reasons. This fixes checkpatch error: > > > > ERROR: Macros starting with if should be enclosed by a do - while > > loop to avoid possible if/else logic defects > > > > Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx> > > This is an improvement, but the macro still has other issues that > are just as bad as the one you address: > > - Using the # operator to avoid the "" in the invocation seems confusing I guess it was useful for debugging. > - it implicitly uses the 'cs' and 't' variables of the calling function instead > of passing them as arguments. Actually another reason to convert it to just a function. > - it calls 'return -1' in a function that otherwise uses errno-style > return codes, so this gets interpreted as EPERM "Operation not > permitted". The users of this macro also do it (gpmc_cs_set_timings()) so this wrong practice is consistent with the driver. :) > > I would probably just open-code the entire thing and remove the > macro like: > > ret = 0; > ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 0, 3, 0, t->cs_on, > GPMC_CD_FCLK, "cs_on"); > ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 8, 12, 0, > t->cs_rd_off, GPMC_CD_FCLK, "cs_rd_off"); > ret |= set_gpmc_timing_reg(cs, GPMC_CS_CONFIG2, 16, 20, 0, > t->cs_wr_off, GPMC_CD_FCLK, "cs_wr_off); > ... > if (ret) > return -ENXIO;a I like this approach because it also removes the 'return' from macro which is not desired. > > Of maybe leave the macro, but remove the if/return part and use > the "ret |= GPMC_SET_ONE(...)" trick to avoid some of the problems. I could probably then keep it as a function. This would be the safest and remove most of the problems here. Best regards, Krzysztof
