diff options
| author | Damien Lespiau <damien.lespiau@intel.com> | 2014-09-04 15:27:23 +0400 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-09-04 17:08:53 +0400 |
| commit | 2789339044fb6dfbee0c8cd77e26438b80e333ee (patch) | |
| tree | 072046d5f05e726246db377fc63e0d31aedeaeab /drivers/gpu/drm/i915 | |
| parent | 951468f33118d1183fd22a5e8450b80a5afc0dd9 (diff) | |
| download | linux-2789339044fb6dfbee0c8cd77e26438b80e333ee.tar.xz | |
drm/i915: Rewrite ABS_DIFF() in a safer manner
The new version of the macro does a few things better:
- protect the arguments,
- only evaluate the arguments once,
- check that the arguments are of the same type,
Change LC_FREQ_2K to be a unsigned 64bit constant and removed the '()'
from the caller as a result.
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ddi.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index eed9a2a82a85..b63d4fa204a3 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -424,7 +424,7 @@ intel_ddi_get_crtc_encoder(struct drm_crtc *crtc) } #define LC_FREQ 2700 -#define LC_FREQ_2K (LC_FREQ * 2000) +#define LC_FREQ_2K U64_C(LC_FREQ * 2000) #define P_MIN 2 #define P_MAX 64 @@ -436,7 +436,11 @@ intel_ddi_get_crtc_encoder(struct drm_crtc *crtc) #define VCO_MIN 2400 #define VCO_MAX 4800 -#define ABS_DIFF(a, b) ((a > b) ? (a - b) : (b - a)) +#define abs_diff(a, b) ({ \ + typeof(a) __a = (a); \ + typeof(b) __b = (b); \ + (void) (&__a == &__b); \ + __a > __b ? (__a - __b) : (__b - __a); }) struct wrpll_rnp { unsigned p, n2, r2; @@ -546,9 +550,9 @@ static void wrpll_update_rnp(uint64_t freq2k, unsigned budget, */ a = freq2k * budget * p * r2; b = freq2k * budget * best->p * best->r2; - diff = ABS_DIFF((freq2k * p * r2), (LC_FREQ_2K * n2)); - diff_best = ABS_DIFF((freq2k * best->p * best->r2), - (LC_FREQ_2K * best->n2)); + diff = abs_diff(freq2k * p * r2, LC_FREQ_2K * n2); + diff_best = abs_diff(freq2k * best->p * best->r2, + LC_FREQ_2K * best->n2); c = 1000000 * diff; d = 1000000 * diff_best; |