From 4fa790421c10e5c9c62406655c06d97a94555d54 Mon Sep 17 00:00:00 2001 From: Damien Lespiau Date: Fri, 8 Aug 2014 19:25:57 +0100 Subject: [PATCH] drm/i915: Fix erroneous conversion to u8 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit adj was defined as u8. The issue is last_adj can be negative and adj is initialized with: adj = dev_priv->rps.last_adj; and we were also happily doing things like: if (adj < 0) (thank static analysers!) v2: Make new_delay an int in case we overflow the u8 in the intermediate computations. new_delay will get clamped at the end anyway. (Ville) Cc: Deepak S Cc: Ville Syrjälä Signed-off-by: Damien Lespiau Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_irq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 87abe8679495..f0d24db76e72 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1327,10 +1327,10 @@ static u32 vlv_c0_residency(struct drm_i915_private *dev_priv, * @dev_priv: DRM device private * */ -static u32 vlv_calc_delay_from_C0_counters(struct drm_i915_private *dev_priv) +static int vlv_calc_delay_from_C0_counters(struct drm_i915_private *dev_priv) { u32 residency_C0_up = 0, residency_C0_down = 0; - u8 new_delay, adj; + int new_delay, adj; dev_priv->rps.ei_interrupt_count++; -- 2.30.2