From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Widawsky Subject: [PATCH 01/12] drm/i915: Fix forcewake counts for gen8 Date: Fri, 21 Mar 2014 11:48:10 -0700 Message-ID: <1395427701-13434-2-git-send-email-benjamin.widawsky@linux.intel.com> References: <1395427701-13434-1-git-send-email-benjamin.widawsky@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1395427701-13434-1-git-send-email-benjamin.widawsky@linux.intel.com> Sender: stable-owner@vger.kernel.org To: Intel GFX Cc: Mika Kuoppala , =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= , stable@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org =46rom: Mika Kuoppala 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. =46ix 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=3D74007 Cc: Ville Syrj=C3=A4l=C3=A4 Signed-off-by: Mika Kuoppala Signed-off-by: Daniel Vetter [BDW 3.14 backport] Cc: stable@vger.kernel.org Signed-off-by: Ben Widawsky --- 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 87df68f..6df5ec4 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_priv= ate *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 =3D 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 =3D=3D 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 =3D=3D 0) \ + dev_priv->uncore.funcs.force_wake_put(dev_priv, \ + FORCEWAKE_ALL); \ + } else { \ + __raw_i915_write##x(dev_priv, reg, val); \ } \ REG_WRITE_FOOTER; \ } --=20 1.9.1