| Message ID | 1344398064-13563-5-git-send-email-seanpaul@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wednesday, August 08, 2012 12:54 PM Sean Paul wrote: > > According to the exynos datasheet (Figure 49-10), we should wait for PLL > lock before programming the training pattern when doing software eDP > link training. > > Signed-off-by: Sean Paul <seanpaul@chromium.org> > Reviewed-by: Mandeep Singh Baines <msb@chromium.org> > --- > drivers/video/exynos/exynos_dp_core.c | 14 +++++++++++++- > 1 files changed, 13 insertions(+), 1 deletions(-) > > diff --git a/drivers/video/exynos/exynos_dp_core.c b/drivers/video/exynos/exynos_dp_core.c > index 3deded2..207bd7e 100644 > --- a/drivers/video/exynos/exynos_dp_core.c > +++ b/drivers/video/exynos/exynos_dp_core.c > @@ -23,6 +23,8 @@ > > #include "exynos_dp_core.h" > > +#define PLL_MAX_TRIES 100 > + > static int exynos_dp_init_dp(struct exynos_dp_device *dp) > { > exynos_dp_reset(dp); > @@ -260,7 +262,7 @@ static void exynos_dp_set_lane_lane_pre_emphasis(struct exynos_dp_device *dp, > > static int exynos_dp_link_start(struct exynos_dp_device *dp) > { > - int ret, lane, lane_count; > + int ret, lane, lane_count, pll_tries; > u8 buf[4]; > > lane_count = dp->link_train.lane_count; > @@ -293,6 +295,16 @@ static int exynos_dp_link_start(struct exynos_dp_device *dp) > exynos_dp_set_lane_lane_pre_emphasis(dp, > PRE_EMPHASIS_LEVEL_0, lane); > > + /* Wait for PLL lock */ > + pll_tries = 0; > + while (exynos_dp_get_pll_lock_status(dp) == PLL_UNLOCKED) { > + if (pll_tries == PLL_MAX_TRIES) > + return -ETIMEDOUT; > + > + pll_tries++; > + udelay(100); > + } > + You don't need to add 'PLL_MAX_TRIES', please use 'DP_TIMEOUT_LOOP_COUNT' as below: /* Wait for PLL lock */ while (exynos_dp_get_pll_lock_status(dp) == PLL_UNLOCKED) { timeout_loop++; if (DP_TIMEOUT_LOOP_COUNT < timeout_loop) { dev_err(dp->dev, "failed to get pll lock status\n"); return -ETIMEDOUT; } udelay(100); } Also, could you use usleep_range() instead of udelay()? > /* Set training pattern 1 */ > exynos_dp_set_training_pattern(dp, TRAINING_PTN1); > > -- > 1.7.7.3 -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/video/exynos/exynos_dp_core.c b/drivers/video/exynos/exynos_dp_core.c index 3deded2..207bd7e 100644 --- a/drivers/video/exynos/exynos_dp_core.c +++ b/drivers/video/exynos/exynos_dp_core.c @@ -23,6 +23,8 @@ #include "exynos_dp_core.h" +#define PLL_MAX_TRIES 100 + static int exynos_dp_init_dp(struct exynos_dp_device *dp) { exynos_dp_reset(dp); @@ -260,7 +262,7 @@ static void exynos_dp_set_lane_lane_pre_emphasis(struct exynos_dp_device *dp, static int exynos_dp_link_start(struct exynos_dp_device *dp) { - int ret, lane, lane_count; + int ret, lane, lane_count, pll_tries; u8 buf[4]; lane_count = dp->link_train.lane_count; @@ -293,6 +295,16 @@ static int exynos_dp_link_start(struct exynos_dp_device *dp) exynos_dp_set_lane_lane_pre_emphasis(dp, PRE_EMPHASIS_LEVEL_0, lane); + /* Wait for PLL lock */ + pll_tries = 0; + while (exynos_dp_get_pll_lock_status(dp) == PLL_UNLOCKED) { + if (pll_tries == PLL_MAX_TRIES) + return -ETIMEDOUT; + + pll_tries++; + udelay(100); + } + /* Set training pattern 1 */ exynos_dp_set_training_pattern(dp, TRAINING_PTN1);