| Message ID | 20180112201553.683979009@cogentembedded.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sergei, Thank you for the patch. On Friday, 12 January 2018 22:12:05 EET Sergei Shtylyov wrote: > According to the latest revision 2.00 of the R-Car gen2 manual, the LVDS > must be enabled and the bias crcuit enabled after the LVDS I/O pins are > enabled, not before -- fix the gen2 LVDS startup sequence accordingly. > > Fixes: 90374b5c25c9 ("drm/rcar-du: Add internal LVDS encoder support") > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> > > --- > drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c | 11 ++++++----- > 1 file changed, 6 insertions(+), 5 deletions(-) > > Index: linux/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c > =================================================================== > --- linux.orig/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c > +++ linux/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c > @@ -59,11 +59,8 @@ static void rcar_du_lvdsenc_start_gen2(s > > rcar_lvds_write(lvds, LVDPLLCR, pllcr); > > - /* > - * Set the LVDS mode, select the input, enable LVDS operation, > - * and turn bias circuitry on. > - */ > - lvdcr0 = (lvds->mode << LVDCR0_LVMD_SHIFT) | LVDCR0_BEN | LVDCR0_LVEN; > + /* Select the input and set the LVDS mode. */ > + lvdcr0 = lvds->mode << LVDCR0_LVMD_SHIFT; > if (rcrtc->index == 2) > lvdcr0 |= LVDCR0_DUSEL; > rcar_lvds_write(lvds, LVDCR0, lvdcr0); > @@ -73,6 +70,10 @@ static void rcar_du_lvdsenc_start_gen2(s > LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) | > LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY); > > + /* Enable LVDS operation and turn bias circuitry on. */ > + lvdcr0 |= LVDCR0_BEN | LVDCR0_LVEN; > + rcar_lvds_write(lvds, LVDCR0, lvdcr0); This change looks good, but for the reasons explained in my replies to patch 1/2, I would set the mode here along with the BEN and LVEN bits. > /* > * Turn the PLL on, wait for the startup delay, and turn the output > * on.
Index: linux/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c =================================================================== --- linux.orig/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c +++ linux/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c @@ -59,11 +59,8 @@ static void rcar_du_lvdsenc_start_gen2(s rcar_lvds_write(lvds, LVDPLLCR, pllcr); - /* - * Set the LVDS mode, select the input, enable LVDS operation, - * and turn bias circuitry on. - */ - lvdcr0 = (lvds->mode << LVDCR0_LVMD_SHIFT) | LVDCR0_BEN | LVDCR0_LVEN; + /* Select the input and set the LVDS mode. */ + lvdcr0 = lvds->mode << LVDCR0_LVMD_SHIFT; if (rcrtc->index == 2) lvdcr0 |= LVDCR0_DUSEL; rcar_lvds_write(lvds, LVDCR0, lvdcr0); @@ -73,6 +70,10 @@ static void rcar_du_lvdsenc_start_gen2(s LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) | LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY); + /* Enable LVDS operation and turn bias circuitry on. */ + lvdcr0 |= LVDCR0_BEN | LVDCR0_LVEN; + rcar_lvds_write(lvds, LVDCR0, lvdcr0); + /* * Turn the PLL on, wait for the startup delay, and turn the output * on.
According to the latest revision 2.00 of the R-Car gen2 manual, the LVDS must be enabled and the bias crcuit enabled after the LVDS I/O pins are enabled, not before -- fix the gen2 LVDS startup sequence accordingly. Fixes: 90374b5c25c9 ("drm/rcar-du: Add internal LVDS encoder support") Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> --- drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)