| Message ID | 20190503122949.12266-13-tomi.valkeinen@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/bridge: tc358767: DP support | expand |
On 03.05.2019 14:29, Tomi Valkeinen wrote: > Link training will sometimes fail if the DP link is enabled when > tc_main_link_enable() is called. The driver makes sure the DP link is > disabled when the DP output is disabled, and we never enable the DP > without first disabling it, so this should never happen. > > However, as the HW behavior seems to be somewhat random if DP link has > erroneously been left enabled, let's add a WARN_ON() for the case and > set DP0CTL to 0. > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> -- Regards Andrzej
diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index 86e2e16c5a90..cec825600158 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -839,6 +839,10 @@ static int tc_main_link_enable(struct tc_data *tc) dev_dbg(tc->dev, "link enable\n"); + tc_read(DP0CTL, &value); + if (WARN_ON(value != 0)) + tc_write(DP0CTL, 0); + tc_write(DP0_SRCCTRL, tc_srcctrl(tc)); /* SSCG and BW27 on DP1 must be set to the same as on DP0 */ tc_write(DP1_SRCCTRL,
Link training will sometimes fail if the DP link is enabled when tc_main_link_enable() is called. The driver makes sure the DP link is disabled when the DP output is disabled, and we never enable the DP without first disabling it, so this should never happen. However, as the HW behavior seems to be somewhat random if DP link has erroneously been left enabled, let's add a WARN_ON() for the case and set DP0CTL to 0. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> --- drivers/gpu/drm/bridge/tc358767.c | 4 ++++ 1 file changed, 4 insertions(+)