From 40f1b87ce7f84a7ff74fd519dc2c75b333068815 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sat, 20 Dec 2014 15:15:23 +0100 Subject: [PATCH] sunxi: video: Give hotplug-detect (hpd) signal some time to show up When using a hdmi powered hdmi to vga dongle, and cold booting a sunxi device, the hpd detect code would not see the dongle (until a warm reboot), because the dongle needs some time to boot. Testing has shown that this dongle needs 213ms to respond on a cold boot, so wait up to 300ms for a hpd signal to show up before giving up. Signed-off-by: Hans de Goede Acked-by: Ian Campbell Acked-by: Anatolij Gustschin --- drivers/video/sunxi_display.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/video/sunxi_display.c b/drivers/video/sunxi_display.c index 795835de8e..5a14785666 100644 --- a/drivers/video/sunxi_display.c +++ b/drivers/video/sunxi_display.c @@ -48,6 +48,7 @@ static int sunxi_hdmi_hpd_detect(void) (struct sunxi_ccm_reg *)SUNXI_CCM_BASE; struct sunxi_hdmi_reg * const hdmi = (struct sunxi_hdmi_reg *)SUNXI_HDMI_BASE; + unsigned long tmo = timer_get_us() + 300000; /* Set pll3 to 300MHz */ clock_set_pll3(300000000); @@ -68,9 +69,12 @@ static int sunxi_hdmi_hpd_detect(void) writel(SUNXI_HDMI_CTRL_ENABLE, &hdmi->ctrl); writel(SUNXI_HDMI_PAD_CTRL0_HDP, &hdmi->pad_ctrl0); - udelay(1000); + while (timer_get_us() < tmo) { + if (readl(&hdmi->hpd) & SUNXI_HDMI_HPD_DETECT) + return 1; + } - return (readl(&hdmi->hpd) & SUNXI_HDMI_HPD_DETECT) ? 1 : 0; + return 0; } static void sunxi_hdmi_shutdown(void) -- 2.25.1