On Thursday, November 01, 2012 2:05 AM Sean Paul wrote > > On Mon, Aug 20, 2012 at 5:19 AM, Jingoo Han <jg1.han@xxxxxxxxxxx> wrote: > > On Wednesday, August 08, 2012 12:54 PM Sean Paul wrote: > >> > >> Don't reset the sink power to D0. Removing this for three reasons: > >> > >> 1) It's not required in the SW link training documentation > > OK. > >> 2) The comment is incorrect, D0 is normal operation, not "power down" > > OK. As you mentioned, D0 is not 'power down', 'normal operation'. > > However, if comment is wrong, usually we fix comment, not remove it. :) > > > > The datasheet doesn't mention this step at all. Furthermore, the > comment explains how it *should* work, so I think it's the code that > is in error. Do you know why this code is needed? This is not requirement of the datasheet. Also, D0 is not necessary for Link training. Um, this is work-around for initial development. Newly developed panel did not work, due to pane problem, so this work-around was added. However, the panel problem was fixed, so this code is not necessary. Please replace comment as below: According to DP spec, it is not required in the Link Training procedure. Best regards, Jingoo Han > > >> 3) It seems to change things in the link training that causes glitches > > > > Um, it seems that this problem depends on LCD panel. > > Other LCDs that I have tested do not have this kind of problem. > > Please, modify this comment. > > > > That was a red herring, it didn't cause the glitches, just made them > less obvious. > > Sean > > >> > >> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx> > >> --- > >> drivers/video/exynos/exynos_dp_core.c | 6 ------ > >> 1 files changed, 0 insertions(+), 6 deletions(-) > >> > >> diff --git a/drivers/video/exynos/exynos_dp_core.c b/drivers/video/exynos/exynos_dp_core.c > >> index 207bd7e..1c998d9 100644 > >> --- a/drivers/video/exynos/exynos_dp_core.c > >> +++ b/drivers/video/exynos/exynos_dp_core.c > >> @@ -273,12 +273,6 @@ static int exynos_dp_link_start(struct exynos_dp_device *dp) > >> for (lane = 0; lane < lane_count; lane++) > >> dp->link_train.cr_loop[lane] = 0; > >> > >> - /* Set sink to D0 (Sink Not Ready) mode. */ > >> - ret = exynos_dp_write_byte_to_dpcd(dp, DPCD_ADDR_SINK_POWER_STATE, > >> - DPCD_SET_POWER_STATE_D0); > >> - if (ret) > >> - return ret; > >> - > >> /* Set link rate and count as you want to establish*/ > >> exynos_dp_set_link_bandwidth(dp, dp->link_train.link_rate); > >> exynos_dp_set_lane_count(dp, dp->link_train.lane_count); > >> -- > >> 1.7.7.3 > > -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
