lkml.org 
[lkml]   [2012]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    SubjectRe: [PATCH 14/14 v5] drm/i915/intel_i2c: remove POSTING_READ() from gmbus transfers
    Date
    On Wed, 28 Mar 2012 20:51:57 +0800, Daniel Kurtz <djkurtz@chromium.org> wrote:
    > The POSTING_READ() calls were originally added to make sure the writes
    > were flushed before any timing delays and across loops.
    > However, the normal I915_READ() and I915_WRITE() macros already call
    > readl() / writel(), which already have an explicit mb().
    >
    > Now that the code has settled a bit, let's remove them.
    >
    > Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
    > ---
    > drivers/gpu/drm/i915/intel_i2c.c | 5 -----
    > 1 files changed, 0 insertions(+), 5 deletions(-)
    >
    > diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
    > index 2865313..be2852e 100644
    > --- a/drivers/gpu/drm/i915/intel_i2c.c
    > +++ b/drivers/gpu/drm/i915/intel_i2c.c
    > @@ -131,7 +131,6 @@ static void set_clock(void *data, int state_high)
    > GPIO_CLOCK_VAL_MASK;
    >
    > I915_WRITE_NOTRACE(bus->gpio_reg, reserved | clock_bits);
    > - POSTING_READ(bus->gpio_reg);
    We do need the write flush here (and set_data) as the next action is a
    udelay loop which is not per-se a mb.
    -Chris

    --
    Chris Wilson, Intel Open Source Technology Centre


    \
     
     \ /
      Last update: 2012-03-28 15:07    [W:0.021 / U:0.028 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site