Re: msm8996: qcom-qmp: apq8096-db820c fails to boot, reset back to fastboot and locks up

[Niklas Cassel <niklas.cassel@linaro.org>]

On Wed, Jun 12, 2019 at 04:09:11PM +0200, Paolo Pisati wrote:
> On Wed, Jun 12, 2019 at 03:17:35PM +0200, Niklas Cassel wrote:
> > > diff --git a/drivers/phy/qualcomm/phy-qcom-qmp.c b/drivers/phy/qualcomm/phy-qcom-qmp.c
> > > index cd91b4179b10..22352e3b0ec5 100644
> > > --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> > > +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> > > @@ -1490,7 +1490,7 @@ static int qcom_qmp_phy_enable(struct phy *phy)
> > >  
> > >         ret = qcom_qmp_phy_com_init(qphy);
> > >         if (ret)
> > > -               return ret;
> > > +               goto err_lane_rst;
> > >  
> > >         if (cfg->has_lane_rst) {
> > >                 ret = reset_control_deassert(qphy->lane_rst);
> 
> Hi Niklas,
> unfortunately, it didn't help - i added a printk, to highlight when it failed:
> 
> --- a/drivers/phy/qualcomm/phy-qcom-qmp.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp.c
> @@ -1489,8 +1489,10 @@ static int qcom_qmp_phy_enable(struct phy *phy)
>         }
>  
>         ret = qcom_qmp_phy_com_init(qphy);
> -       if (ret)
> -               return ret;
> +       if (ret) {
> +               dev_err(qmp->dev, "qphy initialization failed\n");
> +               goto err_lane_rst;
> +       }
>  
>         if (cfg->has_lane_rst) {
>                 ret = reset_control_deassert(qphy->lane_rst);
> 
> After several reboots i was able to trigger the phy init failure again:
> 
> ...
> [    2.223999] qcom-qmp-phy 34000.phy: Registered Qcom-QMP phy
> [    2.224956] qcom-qmp-phy 7410000.phy: Registered Qcom-QMP phy
> [    2.228798] ufs_qcom_phy_qmp_14nm 627000.phy: invalid resource
> [    2.237271] qcom-qmp-phy 34000.phy: phy common block init timed-out
> [    2.240315] qcom-qmp-phy 34000.phy: qphy initialization failed
> ...

I still think that the above patch is correct,
even though it didn't fix your problem.

If you try to disable the two other PCIe controllers:

diff --git a/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi b/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi
index 943f69912074..95900fe99f89 100644
--- a/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi
+++ b/arch/arm64/boot/dts/qcom/apq8096-db820c.dtsi
@@ -455,12 +455,12 @@
                        };
 
                        pcie@608000 {
-                               status = "okay";
+                               status = "disabled";
                                perst-gpio = <&msmgpio 130 GPIO_ACTIVE_LOW>;
                        };
 
                        pcie@610000 {
-                               status = "okay";
+                               status = "disabled";
                                perst-gpio = <&msmgpio 114 GPIO_ACTIVE_LOW>;
                        };
                };


Can you still reproduce the reboot?


Kind regards,
Niklas

> 
> these are the last lines printed, before rebooting in fastboot and
> locking up there (as before[*]).
> 
> So, as far as i understand there are two distinct problems:
> 
> 1) sometimes, qcom-qmp-phy fails to initialize
> 
> 2) and when that happens, the failure is fatal and it led to a reboot & lockup
> in fastboot
> 
> 1: https://pastebin.ubuntu.com/p/rtjVrD3yzk/
> -- 
> bye,
> p.