Hello Joonyoung, On Fri, Jan 30, 2015 at 3:02 AM, Joonyoung Shim <jy0922.shim@xxxxxxxxxxx> wrote: > +Cc Kukjin, > > Hi, > > On 01/29/2015 10:31 PM, Gustavo Padovan wrote: >> From: Prathyush K <prathyush.k@xxxxxxxxxxx> >> >> When VPLL clock of less than 140 MHz was used and all the three >> clocks - hdmiphy, hdmi, sclk_hdmi are disabled, the system hangs >> during S2R when HDMI is connected. Since we want to use a vpll >> clock of 70.5 MHz, we cannot disable these 3 clocks before suspending. >> This patch moves the clk enable/disable of hdmi and sclk_hdmi >> outside of the pm ops. Now system suspends and resumes with HDMI >> connected with VPLL set at 70.5 MHz. >> >> Signed-off-by: Prathyush K <prathyush.k@xxxxxxxxxxx> >> Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx> >> Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxxxx> >> >> --- >> This work depends on the HDMI support patches from Javier: >> https://lkml.org/lkml/2015/1/20/235 >> >> This patch comes from a downstream tree (Google chormeOS) and it is >> authored by a Samsung employee, but we still think this may not fix >> the real cause of the bug, there might be something else that we >> haven't found that could be the cause of this issue. Anyone has some >> comment to add here? > > Hmm, do you test from which exynos SoC? > I haven't the S2R case since it is broken in mainline for Exynos5420 (even with $subject applied) but $subject fixes for me the system crash we have discussed before [0]. That is when mixer_poweron() tries to access the mixer register without hdmi_poweron() enabling the "hdmi" clock. > Kukjin, if it is hw issue, do you know hw experts of exynos hdmi and > could we get any advice? > It would be great if someone can shed some light on both issues. >> --- >> drivers/gpu/drm/exynos/exynos_hdmi.c | 17 +++++++++++------ >> 1 file changed, 11 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c >> index 6aa0d65..7a473cb 100644 >> --- a/drivers/gpu/drm/exynos/exynos_hdmi.c >> +++ b/drivers/gpu/drm/exynos/exynos_hdmi.c >> @@ -2064,9 +2064,6 @@ static void hdmi_poweron(struct exynos_drm_display *display) >> regmap_update_bits(hdata->pmureg, PMU_HDMI_PHY_CONTROL, >> PMU_HDMI_PHY_ENABLE_BIT, 1); >> >> - clk_prepare_enable(res->hdmi); >> - clk_prepare_enable(res->sclk_hdmi); >> - >> hdmiphy_poweron(hdata); >> hdmi_commit(display); >> } >> @@ -2088,9 +2085,6 @@ static void hdmi_poweroff(struct exynos_drm_display *display) >> >> cancel_delayed_work(&hdata->hotplug_work); >> >> - clk_disable_unprepare(res->sclk_hdmi); >> - clk_disable_unprepare(res->hdmi); >> - >> /* reset pmu hdmiphy control bit to disable hdmiphy */ >> regmap_update_bits(hdata->pmureg, PMU_HDMI_PHY_CONTROL, >> PMU_HDMI_PHY_ENABLE_BIT, 0); >> @@ -2254,6 +2248,14 @@ static int hdmi_resources_init(struct hdmi_context *hdata) >> } else >> res->reg_hdmi_en = NULL; >> >> + /* >> + * These two clocks are not moved into hdmi_poweron/off since system >> + * fails to suspend if VPLL clock of 70.5 MHz is used and these >> + * clocks are disabled before suspend. So enable them here. >> + */ >> + clk_prepare_enable(res->sclk_hdmi); >> + clk_prepare_enable(res->hdmi); >> + > > Then twe clocks are turned on always. I don't think it's reasonable. > Agreed that it would be better to gate/ungate the clocks as necessary to reduce power consumption but OTOH is better to leave some clocks enabled to avoid system crashes. Of course it would be even better to understand the root cause and fix it. Best regards, Javier -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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