| Message ID | 20190326103146.24795-13-tomi.valkeinen@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/bridge: tc358767: DP support | expand |
On 26.03.2019 11:31, Tomi Valkeinen wrote: > For some reason the driver has a msleep(100) after writing to > DP_PHY_CTRL. Toshiba's documentation doesn't suggest any delay is > needed, and I have not seen any issues with the sleep removed. > > Drop it, as msleep(100) is a rather big one. > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com> -- Regards Andrzej > --- > drivers/gpu/drm/bridge/tc358767.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c > index f628575c9de9..2a6c0c0d47a6 100644 > --- a/drivers/gpu/drm/bridge/tc358767.c > +++ b/drivers/gpu/drm/bridge/tc358767.c > @@ -872,7 +872,6 @@ static int tc_main_link_enable(struct tc_data *tc) > if (tc->link.base.num_lanes == 2) > dp_phy_ctrl |= PHY_2LANE; > tc_write(DP_PHY_CTRL, dp_phy_ctrl); > - msleep(100); > > /* PLL setup */ > tc_write(DP0_PLLCTRL, PLLUPDATE | PLLEN);
Hi Tomi, Thank you for the patch. On Tue, Mar 26, 2019 at 12:31:36PM +0200, Tomi Valkeinen wrote: > For some reason the driver has a msleep(100) after writing to > DP_PHY_CTRL. Toshiba's documentation doesn't suggest any delay is > needed, and I have not seen any issues with the sleep removed. I can't comment on this as I don't have access to the datasheet. The code change itself is fine. Andrey, do you remember why a sleep was added there in the first place ? > Drop it, as msleep(100) is a rather big one. > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> > --- > drivers/gpu/drm/bridge/tc358767.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c > index f628575c9de9..2a6c0c0d47a6 100644 > --- a/drivers/gpu/drm/bridge/tc358767.c > +++ b/drivers/gpu/drm/bridge/tc358767.c > @@ -872,7 +872,6 @@ static int tc_main_link_enable(struct tc_data *tc) > if (tc->link.base.num_lanes == 2) > dp_phy_ctrl |= PHY_2LANE; > tc_write(DP_PHY_CTRL, dp_phy_ctrl); > - msleep(100); > > /* PLL setup */ > tc_write(DP0_PLLCTRL, PLLUPDATE | PLLEN);
Hi On Sun, Apr 21, 2019 at 12:43 AM Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > > Hi Tomi, > > Thank you for the patch. > > On Tue, Mar 26, 2019 at 12:31:36PM +0200, Tomi Valkeinen wrote: > > For some reason the driver has a msleep(100) after writing to > > DP_PHY_CTRL. Toshiba's documentation doesn't suggest any delay is > > needed, and I have not seen any issues with the sleep removed. > > I can't comment on this as I don't have access to the datasheet. The > code change itself is fine. > > Andrey, do you remember why a sleep was added there in the first place ? I see no reason for this delay. Seems this was not cleaned-up after debug. Reviewed-by: Andrey Gusakov <andrey.gusakov@cogentembedded.com> > > > Drop it, as msleep(100) is a rather big one. > > > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> > > --- > > drivers/gpu/drm/bridge/tc358767.c | 1 - > > 1 file changed, 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c > > index f628575c9de9..2a6c0c0d47a6 100644 > > --- a/drivers/gpu/drm/bridge/tc358767.c > > +++ b/drivers/gpu/drm/bridge/tc358767.c > > @@ -872,7 +872,6 @@ static int tc_main_link_enable(struct tc_data *tc) > > if (tc->link.base.num_lanes == 2) > > dp_phy_ctrl |= PHY_2LANE; > > tc_write(DP_PHY_CTRL, dp_phy_ctrl); > > - msleep(100); > > > > /* PLL setup */ > > tc_write(DP0_PLLCTRL, PLLUPDATE | PLLEN); > > -- > Regards, > > Laurent Pinchart
diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c index f628575c9de9..2a6c0c0d47a6 100644 --- a/drivers/gpu/drm/bridge/tc358767.c +++ b/drivers/gpu/drm/bridge/tc358767.c @@ -872,7 +872,6 @@ static int tc_main_link_enable(struct tc_data *tc) if (tc->link.base.num_lanes == 2) dp_phy_ctrl |= PHY_2LANE; tc_write(DP_PHY_CTRL, dp_phy_ctrl); - msleep(100); /* PLL setup */ tc_write(DP0_PLLCTRL, PLLUPDATE | PLLEN);
For some reason the driver has a msleep(100) after writing to DP_PHY_CTRL. Toshiba's documentation doesn't suggest any delay is needed, and I have not seen any issues with the sleep removed. Drop it, as msleep(100) is a rather big one. Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com> --- drivers/gpu/drm/bridge/tc358767.c | 1 - 1 file changed, 1 deletion(-)