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authorDamien Lespiau2014-09-04 13:27:23 +0200
committerDaniel Vetter2014-09-04 15:08:53 +0200
commit2789339044fb6dfbee0c8cd77e26438b80e333ee (patch)
tree072046d5f05e726246db377fc63e0d31aedeaeab /drivers/gpu/drm/i915/intel_ddi.c
parentdrm/i915: Add comments explaining the vdd on/off functions (diff)
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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/intel_ddi.c')
-rw-r--r--drivers/gpu/drm/i915/intel_ddi.c14
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;