mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-25 10:19:47 +00:00
drm/i915: Use mul_u32_u32() for 32b x 32b -> 64b result
As realised by commit 9e3d6223d2
("math64, timers: Fix 32bit
mul_u64_u32_shr() and friends"), GCC does not always generate ideal code
for performing a 32b x 32b multiply returning a 64b result (i.e. where
we idiomatically use u64 result = (u64)x * (u32)x). This catches a
couple of instances in the display code using (u64)x * (u32)y.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20170913105154.2910-1-chris@chris-wilson.co.uk
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
This commit is contained in:
parent
e60b36f76c
commit
3123698f50
2 changed files with 2 additions and 2 deletions
|
@ -10224,7 +10224,7 @@ int intel_dotclock_calculate(int link_freq,
|
|||
if (!m_n->link_n)
|
||||
return 0;
|
||||
|
||||
return div_u64((u64)m_n->link_m * link_freq, m_n->link_n);
|
||||
return div_u64(mul_u32_u32(m_n->link_m, link_freq), m_n->link_n);
|
||||
}
|
||||
|
||||
static void ironlake_pch_clock_get(struct intel_crtc *crtc,
|
||||
|
|
|
@ -1385,7 +1385,7 @@ intel_tv_get_modes(struct drm_connector *connector)
|
|||
mode_ptr->vsync_end = mode_ptr->vsync_start + 1;
|
||||
mode_ptr->vtotal = vactive_s + 33;
|
||||
|
||||
tmp = (u64) tv_mode->refresh * mode_ptr->vtotal;
|
||||
tmp = mul_u32_u32(tv_mode->refresh, mode_ptr->vtotal);
|
||||
tmp *= mode_ptr->htotal;
|
||||
tmp = div_u64(tmp, 1000000);
|
||||
mode_ptr->clock = (int) tmp;
|
||||
|
|
Loading…
Reference in a new issue