3.16.7-ckt17 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Chris Wilson <[email protected]> commit ee0a227b7ac6e75f28e10269f81c7ec6eb600952 upstream. Since we may conceivably encounter situations where the upper part of the 64bit register changes between reads, for example when a timestamp counter overflows, change the WARN into a retry loop. Signed-off-by: Chris Wilson <[email protected]> Cc: Michał Winiarski <[email protected]> Signed-off-by: Daniel Vetter <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- drivers/gpu/drm/i915/i915_drv.h | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 28c7afdfffbc..67f72fa5a769 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2682,15 +2682,14 @@ int vlv_freq_opcode(struct drm_i915_private *dev_priv, int val); #define I915_READ64(reg) dev_priv->uncore.funcs.mmio_readq(dev_priv, (reg), true) #define I915_READ64_2x32(lower_reg, upper_reg) ({ \ - u32 upper = I915_READ(upper_reg); \ - u32 lower = I915_READ(lower_reg); \ - u32 tmp = I915_READ(upper_reg); \ - if (upper != tmp) { \ - upper = tmp; \ - lower = I915_READ(lower_reg); \ - WARN_ON(I915_READ(upper_reg) != upper); \ - } \ - (u64)upper << 32 | lower; }) + u32 upper, lower, tmp; \ + tmp = I915_READ(upper_reg); \ + do { \ + upper = tmp; \ + lower = I915_READ(lower_reg); \ + tmp = I915_READ(upper_reg); \ + } while (upper != tmp); \ + (u64)upper << 32 | lower; }) #define POSTING_READ(reg) (void)I915_READ_NOTRACE(reg) #define POSTING_READ16(reg) (void)I915_READ16_NOTRACE(reg) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
