| Message ID | 20181106153930.21915-1-laurent.pinchart+renesas@ideasonboard.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
| Series | drm: rcar-du: Fix external clock error checks | expand |
Hi Laurent, Thank you for the patch, On 06/11/2018 15:39, Laurent Pinchart wrote: > The rcar-du driver supports probe deferral for external clocks, but > implements it badly by checking the wrong pointer due to a bad copy and > paste. Fix it. > > While at it, reject invalid clocks outright for DU channels that have a > display PLL, as the external clock is mandatory in that case. This > avoids a WARN_ON() at runtime. > > Fixes: 1b30dbde8596 ("drm: rcar-du: Add support for external pixel clock") > Reported-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> This looks good to me: Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > --- > drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c > index d18a342626b5..79021d7aa3ce 100644 > --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c > +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c > @@ -226,9 +226,6 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc) > * system clock, and have no internal clock divider. > */ > > - if (WARN_ON(!rcrtc->extclock)) > - return; > - > /* > * The H3 ES1.x exhibits dot clock duty cycle stability issues. > * We can work around them by configuring the DPLL to twice the > @@ -1113,9 +1110,16 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int swindex, > clk = devm_clk_get(rcdu->dev, clk_name); > if (!IS_ERR(clk)) { > rcrtc->extclock = clk; > - } else if (PTR_ERR(rcrtc->clock) == -EPROBE_DEFER) { > - dev_info(rcdu->dev, "can't get external clock %u\n", hwindex); > + } else if (PTR_ERR(clk) == -EPROBE_DEFER) { > return -EPROBE_DEFER; > + } else if (rcdu->info->dpll_mask & BIT(hwindex)) { > + /* > + * DU channels that have a display PLL can't use the internal > + * system clock and thus require an external clock. > + */ > + ret = PTR_ERR(clk); > + dev_err(rcdu->dev, "can't get dclkin.%u: %d\n", hwindex, ret); > + return ret; > } > > init_waitqueue_head(&rcrtc->flip_wait); >
diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index d18a342626b5..79021d7aa3ce 100644 --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c @@ -226,9 +226,6 @@ static void rcar_du_crtc_set_display_timing(struct rcar_du_crtc *rcrtc) * system clock, and have no internal clock divider. */ - if (WARN_ON(!rcrtc->extclock)) - return; - /* * The H3 ES1.x exhibits dot clock duty cycle stability issues. * We can work around them by configuring the DPLL to twice the @@ -1113,9 +1110,16 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int swindex, clk = devm_clk_get(rcdu->dev, clk_name); if (!IS_ERR(clk)) { rcrtc->extclock = clk; - } else if (PTR_ERR(rcrtc->clock) == -EPROBE_DEFER) { - dev_info(rcdu->dev, "can't get external clock %u\n", hwindex); + } else if (PTR_ERR(clk) == -EPROBE_DEFER) { return -EPROBE_DEFER; + } else if (rcdu->info->dpll_mask & BIT(hwindex)) { + /* + * DU channels that have a display PLL can't use the internal + * system clock and thus require an external clock. + */ + ret = PTR_ERR(clk); + dev_err(rcdu->dev, "can't get dclkin.%u: %d\n", hwindex, ret); + return ret; } init_waitqueue_head(&rcrtc->flip_wait);
The rcar-du driver supports probe deferral for external clocks, but implements it badly by checking the wrong pointer due to a bad copy and paste. Fix it. While at it, reject invalid clocks outright for DU channels that have a display PLL, as the external clock is mandatory in that case. This avoids a WARN_ON() at runtime. Fixes: 1b30dbde8596 ("drm: rcar-du: Add support for external pixel clock") Reported-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> --- drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)