[PATCHv2 06/22] drm/bridge: tc358767: cleanup aux_link_setup

[Laurent Pinchart]

Hi Tomi,

Thank you for the patch.

On Mon, Apr 15, 2019 at 10:52:38AM +0300, Tomi Valkeinen wrote:
> On 15/04/2019 10:38, Andrzej Hajda wrote:
> > On 26.03.2019 11:31, Tomi Valkeinen wrote:
> >> Modify aux_link_setup so that it does not use tc->link, and thus makes
> >> aux setup independent of the link probing.
> >>
> >> Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
> >> ---
> >>  drivers/gpu/drm/bridge/tc358767.c | 9 +++------
> >>  1 file changed, 3 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> >> index 7ef8d754b4ff..f5c232a9064e 100644
> >> --- a/drivers/gpu/drm/bridge/tc358767.c
> >> +++ b/drivers/gpu/drm/bridge/tc358767.c
> >> @@ -542,7 +542,6 @@ static int tc_aux_link_setup(struct tc_data *tc)
> >>  	unsigned long rate;
> >>  	u32 value;
> >>  	int ret;
> >> -	u32 dp_phy_ctrl;
> >>  
> >>  	rate = clk_get_rate(tc->refclk);
> >>  	switch (rate) {
> >> @@ -567,10 +566,7 @@ static int tc_aux_link_setup(struct tc_data *tc)
> >>  	value |= SYSCLK_SEL_LSCLK | LSCLK_DIV_2;
> >>  	tc_write(SYS_PLLPARAM, value);
> >>  
> >> -	dp_phy_ctrl = BGREN | PWR_SW_EN | PHY_A0_EN;
> >> -	if (tc->link.base.num_lanes == 2)
> >> -		dp_phy_ctrl |= PHY_2LANE;
> >> -	tc_write(DP_PHY_CTRL, dp_phy_ctrl);
> >> +	tc_write(DP_PHY_CTRL, BGREN | PWR_SW_EN | PHY_A0_EN);
> > 
> > 
> > Description does not explain why removal of PHY_2LANE is OK.
> > 
> > I guess because it is set anyway before training but that needs lurking
> > into the code.
> 
> Good point, the desc is a bit unclear. The reason is that we're setting
> up only AUX here, so anything related to the data-lanes is don't-care.

And also because the tc_aux_link_setup() function is called at probe
time, while the tc_main_link_setup() function is called later and will
overwrite the DP_PHY_CTRL register with bits related to the main link.

With the description fixed,

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>

-- 
Regards,

Laurent Pinchart