On Thu 19 Nov 2020 at 19:04, Guillaume Tucker <guillaume.tuc...@collabora.com> wrote:
> Hi Marc, > > On 19/11/2020 11:58, Marc Zyngier wrote: >> On 2020-11-19 10:26, Neil Armstrong wrote: >>> On 19/11/2020 11:20, Marc Zyngier wrote: >>>> On 2020-11-19 08:50, Guillaume Tucker wrote: >>>>> Please see the automated bisection report below about some kernel >>>>> errors on meson-gxbb-p200. >>>>> >>>>> Reports aren't automatically sent to the public while we're >>>>> trialing new bisection features on kernelci.org, however this one >>>>> looks valid. >>>>> >>>>> The bisection started with next-20201118 but the errors are still >>>>> present in next-20201119. Details for this regression: >>>>> >>>>> https://kernelci.org/test/case/id/5fb6196bfd0127fd68d8d902/ >>>>> >>>>> The first error is: >>>>> >>>>> [ 14.757489] Internal error: synchronous external abort: 96000210 >>>>> [#1] PREEMPT SMP >>>> >>>> Looks like yet another clock ordering setup. I guess different Amlogic >>>> platforms have slightly different ordering requirements. >>>> >>>> Neil, do you have any idea of which platform requires which ordering? >>>> The variability in DT and platforms is pretty difficult to follow (and >>>> I don't think I have such board around). >>> >>> The requirements should be the same, here the init was done before calling >>> dw_hdmi_probe to be sure the clocks and internals resets were deasserted. >>> But since you boot from u-boot already enabling these, it's already active. >>> >>> The solution would be to revert and do some check in meson_dw_hdmi_init() to >>> check if already enabled and do nothing. >> >> A better fix seems to be this, which makes it explicit that there is >> a dependency between some of the registers accessed from meson_dw_hdmi_init() >> and the iahb clock. >> >> Guillaume, can you give this a go on your failing box? > > I confirm it solves the problem. Please add this to your fix > patch if it's OK with you: > > Reported-by: "kernelci.org bot" <b...@kernelci.org> > Tested-by: Guillaume Tucker <guillaume.tuc...@collabora.com> > > > For the record, it passed all the tests when applied on top of > the "bad" revision found by the bisection: > > > http://lava.baylibre.com:10080/scheduler/alljobs?search=v5.10-rc3-1021-gb8668a2e5ea1 > > and the exact same test on the "bad" revision without the fix > consistently showed the error: > > http://lava.baylibre.com:10080/scheduler/job/374176 > > > Thanks, > Guillaume > > >> diff --git a/drivers/gpu/drm/meson/meson_dw_hdmi.c >> b/drivers/gpu/drm/meson/meson_dw_hdmi.c >> index 7f8eea494147..52af8ba94311 100644 >> --- a/drivers/gpu/drm/meson/meson_dw_hdmi.c >> +++ b/drivers/gpu/drm/meson/meson_dw_hdmi.c >> @@ -146,6 +146,7 @@ struct meson_dw_hdmi { >> struct reset_control *hdmitx_ctrl; >> struct reset_control *hdmitx_phy; >> struct clk *hdmi_pclk; >> + struct clk *iahb_clk; >> struct clk *venci_clk; >> struct regulator *hdmi_supply; >> u32 irq_stat; >> @@ -1033,6 +1034,13 @@ static int meson_dw_hdmi_bind(struct device *dev, >> struct device *master, >> } >> clk_prepare_enable(meson_dw_hdmi->hdmi_pclk); >> >> + meson_dw_hdmi->iahb_clk = devm_clk_get(dev, "iahb"); >> + if (IS_ERR(meson_dw_hdmi->iahb_clk)) { >> + dev_err(dev, "Unable to get iahb clk\n"); >> + return PTR_ERR(meson_dw_hdmi->iahb_clk); >> + } >> + clk_prepare_enable(meson_dw_hdmi->iahb_clk); If you guys are going ahead with this fix, this call to clk_prepare_enable() needs to be balanced with clk_disable_unprepare() somehow >> + >> meson_dw_hdmi->venci_clk = devm_clk_get(dev, "venci"); >> if (IS_ERR(meson_dw_hdmi->venci_clk)) { >> dev_err(dev, "Unable to get venci clk\n"); >> @@ -1071,6 +1079,8 @@ static int meson_dw_hdmi_bind(struct device *dev, >> struct device *master, >> >> encoder->possible_crtcs = BIT(0); >> >> + meson_dw_hdmi_init(meson_dw_hdmi); >> + >> DRM_DEBUG_DRIVER("encoder initialized\n"); >> >> /* Bridge / Connector */ >> @@ -1095,8 +1105,6 @@ static int meson_dw_hdmi_bind(struct device *dev, >> struct device *master, >> if (IS_ERR(meson_dw_hdmi->hdmi)) >> return PTR_ERR(meson_dw_hdmi->hdmi); >> >> - meson_dw_hdmi_init(meson_dw_hdmi); >> - >> next_bridge = of_drm_find_bridge(pdev->dev.of_node); >> if (next_bridge) >> drm_bridge_attach(encoder, next_bridge, >> >>
