From 62dc398c8d5441d92bfab0da989f86a4d559c775 Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Tue, 18 Feb 2014 18:59:24 +0200 Subject: [PATCH] drm/i915: Fix forcewake counts for gen8 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sometimes generic driver code gets forcewake explicitly by gen6_gt_force_wake_get(), which check forcewake_count before accessing hardware. However the register access with gen8_write function access low level hw accessors directly, ignoring the forcewake_count. This leads to nested forcewake get from hardware, in ring init and possibly elsewhere, causing forcewake ack clear errors and/or hangs. Fix this by checking the forcewake count also in gen8_write v2: Read side doesn't care about shadowed registers, Remove __needs_put funkiness from gen8_write. (Ville) Improved commit message. References: https://bugs.freedesktop.org/show_bug.cgi?id=74007 Signed-off-by: Mika Kuoppala Cc: Ben Widawsky Cc: Ville Syrjälä Signed-off-by: Mika Kuoppala --- drivers/gpu/drm/i915/intel_uncore.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c index c628414..d1e9d63 100644 --- a/drivers/gpu/drm/i915/intel_uncore.c +++ b/drivers/gpu/drm/i915/intel_uncore.c @@ -634,16 +634,17 @@ static bool is_gen8_shadowed(struct drm_i915_private *dev_priv, u32 reg) #define __gen8_write(x) \ static void \ gen8_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \ - bool __needs_put = reg < 0x40000 && !is_gen8_shadowed(dev_priv, reg); \ REG_WRITE_HEADER; \ - if (__needs_put) { \ - dev_priv->uncore.funcs.force_wake_get(dev_priv, \ - FORCEWAKE_ALL); \ - } \ - __raw_i915_write##x(dev_priv, reg, val); \ - if (__needs_put) { \ - dev_priv->uncore.funcs.force_wake_put(dev_priv, \ - FORCEWAKE_ALL); \ + if (reg < 0x40000 && !is_gen8_shadowed(dev_priv, reg)) { \ + if (dev_priv->uncore.forcewake_count == 0) \ + dev_priv->uncore.funcs.force_wake_get(dev_priv, \ + FORCEWAKE_ALL); \ + __raw_i915_write##x(dev_priv, reg, val); \ + if (dev_priv->uncore.forcewake_count == 0) \ + dev_priv->uncore.funcs.force_wake_put(dev_priv, \ + FORCEWAKE_ALL); \ + } else { \ + __raw_i915_write##x(dev_priv, reg, val); \ } \ REG_WRITE_FOOTER; \ } -- 1.7.9.5