| Date | Thu, 25 Apr 2013 10:36:19 +0200 | Subject | Re: [PATCH 08/32] dmaengine: ste_dma40: Optimise local MAX() macro | From | Linus Walleij <> |
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On Thu, Apr 18, 2013 at 12:11 PM, Lee Jones <lee.jones@linaro.org> wrote:
> The current implementation of the DMA40's local MAX() macro evaluates > its arguments more times than is necessary. This patch strips it > optimises it to only evaluate what's appropriate. > > Cc: Vinod Koul <vinod.koul@intel.com> > Cc: Dan Williams <djbw@fb.com> > Cc: Per Forlin <per.forlin@stericsson.com> > Cc: Rabin Vincent <rabin@rab.in> > Reported-by: Harvey Harrison <harvey.harrison@gmail.com> > Signed-off-by: Lee Jones <lee.jones@linaro.org> (...) > -#define MAX(a, b) (((a) < (b)) ? (b) : (a)) > +#define MAX(a, b) ((a > b) ? a : b)
Much has been said about this patch already, but notice what it is used for instead, one single thing at compile-time:
struct d40_base { (...) u32 reg_val_backup_v4[MAX(BACKUP_REGS_SZ_V4A, BACKUP_REGS_SZ_V4B)]; (...) };
i.e. defining the size of that array at compile-time.
The actual size is figured out in d40_hw_detect_init().
So what about you just devm_kmalloc() that array instead and delete this macro. That is the real fix.
Yours, Linus Walleij
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