From: Laurent Pinchart laurent.pinchart+renesas@ideasonboard.com
[ Upstream commit 63a298f22a6183b5b7536a203596c6570dfcfe8e ]
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 Reviewed-by: Kieran Bingham kieran.bingham+renesas@ideasonboard.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 17741843cf51..40a9afe818a8 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);