Re: [PATCH v6 4/7] drm/rockchip: vop: group vop registers

[Mark yao]

Hi Heiko

On 2017å07æ28æ 09:02, Mark yao wrote:
> Hi Heiko
>
> Thanks for the test.
>
> On 2017å07æ27æ 18:10, Heiko StÃbner wrote:
> > Am Donnerstag, 27. Juli 2017, 11:51:06 CEST schrieb Heiko StÃbner:
> > > Hi Mark,
> > >
> > > Am Mittwoch, 26. Juli 2017, 14:19:25 CEST schrieb Mark Yao:
> > > > Grouping the vop registers facilitates make register
> > > > definition clearer, and also is useful for different vop
> > > > reuse the same group register.
> > > >
> > > > Signed-off-by: Mark Yao <mark.yao@xxxxxxxxxxxxxx>
> > > > ---
> > > >
> > > >   drivers/gpu/drm/rockchip/rockchip_drm_vop.c |  99
> > > >   ++++++++++++------------
> > > >   drivers/gpu/drm/rockchip/rockchip_drm_vop.h |  60 ++++++++-------
> > > >   drivers/gpu/drm/rockchip/rockchip_vop_reg.c | 112
> > > >
> > > > +++++++++++++++------------- 3 files changed, 144 insertions(+), 127
> > > > deletions(-)
> > > This breaks display support on both rk3036 and rk3288 and I end up
> > > with a null pointer dereference in
> > >
> > > [   10.640297] Unable to handle kernel NULL pointer dereference at virtual
> > > address 00000000 [   10.654430] pgd = c0204000
> > > [   10.657452] [00000000] *pgd=00000000
> > > [   10.661473] Internal error: Oops: 5 [#1] SMP ARM
> > > [   10.666635] Modules linked in: snd_pcm media snd_timer phy_rockchip_dp
> > > snd soundcore rockchipdrm dw_hdmi analogix_dp rtc_rk808 pwm_rockchip
> > > clk_rk808 spi_rockchip [   10.682897] CPU: 2 PID: 143 Comm: kworker/2:2 Not
> > > tainted 4.13.0-rc2-01791-g2b86603d0515 #355 [   10.692430] Hardware name:
> > > Rockchip (Device Tree)
> > > [   10.697692] Workqueue: events deferred_probe_work_func
> > > [   10.702152] Linux video capture interface: v2.00
> > > [   10.708590] task: ee38c800 task.stack: ed2e6000
> > > [   10.713656] PC is at vop_reg_set.constprop.4+0x4/0xa8 [rockchipdrm]
> > > [   10.720668] LR is at vop_bind+0x568/0x8a0 [rockchipdrm]
> > The obvious reason for that is
> >
> > > @@ -164,14 +153,20 @@ static inline uint32_t vop_read_reg(struct vop *vop,
> > > uint32_t base, return (vop_readl(vop, base + reg->offset) >> reg->shift) &
> > > reg->mask; }
> > >
> > > -static inline void vop_mask_write(struct vop *vop, uint32_t offset,
> > > -                  uint32_t mask, uint32_t shift, uint32_t v,
> > > -                  bool write_mask, bool relaxed)
> > > +static void vop_reg_set(struct vop *vop, const struct vop_reg *reg,
> > > +            uint32_t _offset, uint32_t _mask, uint32_t v,
> > > +            const char *reg_name)
> > >   {
> > > -    if (!mask)
> > > +    int offset = reg->offset + _offset;
> > > +    int mask = reg->mask & _mask;
> > > +    int shift = reg->shift;
>
> Does the crash is that using reg->offset/mask/shift before !reg checking?

I reproduce this cause, from objdump, it crash on "int mask = reg->mask & _mask; "
Seems difference gcc has difference behavior, my aarch64 gcc maybe optimize it,
only access when the value be used. I think that is the reason why rk3399 works on my test.

I will fix it at next version.

> > > +
> > > +    if (!reg || !reg->mask) {
> > > +        dev_dbg(vop->dev, "Warning: not support %s\n", reg_name);
> > >           return;
> > > +    }
> > where the check for !reg happens after it got already dereferenced.
> > But even with that fixed I end up with
> >
> > on rk3288:
> > [    7.254823] rockchip-vop ff930000.vop: Warning: not support global_regdone_en
> > [    7.262847] rockchip-vop ff930000.vop: Warning: not support gate
> > [    7.269580] rockchip-vop ff930000.vop: Warning: not support gate
> > [    7.302765] rockchip-vop ff940000.vop: Warning: not support global_regdone_en
> > [    7.310758] rockchip-vop ff940000.vop: Warning: not support gate
> > [    7.317475] rockchip-vop ff940000.vop: Warning: not support gate
> > [    7.425724] rockchip-vop ff930000.vop: Warning: not support edp_pin_pol
> > [    7.526298] rockchip-vop ff940000.vop: Warning: not support hdmi_pin_pol
>
> Rk3288 does not support independent pin_pol settings, all output interfaces share the pin_pol register,
> So not support hdmi_pin_pol here is correct.
>
> hdmi pin pol would be set by following register:
>     .pin_pol = VOP_REG(RK3288_DSP_CTRL0, 0xf, 4),
>
> > on rk3036:
> > [   12.389138] rockchip-vop 10118000.vop: Warning: not support global_regdone_en
> > [   12.397324] rockchip-vop 10118000.vop: Warning: not support gate
> > [   12.404165] rockchip-vop 10118000.vop: Warning: not support gate
> > [   13.747361] rockchip-vop 10118000.vop: Warning: not support hdmi_pin_pol
> > [   13.747371] rockchip-vop 10118000.vop: Warning: not support hdmi_en
> > [   13.747379] rockchip-vop 10118000.vop: Warning: not support hpost_st_end
> > [   13.747385] rockchip-vop 10118000.vop: Warning: not support vpost_st_end
> > [   13.747461] rockchip-vop 10118000.vop: Warning: not support src_alpha_ctl
> > [   13.767098] rockchip-vop 10118000.vop: Warning: not support src_alpha_ctl
> > [   13.786060] rockchip-vop 10118000.vop: Warning: not support src_alpha_ctl
> >
> > While reqdone and friends are obviously features of newer vops, at least
> > the hdmi pin-pol is available on both these socs.
> >
> > With this patch applied (and null-ptr fixed) I end up without hdmi output
> > on both socs.
>
> Hmmm, I am confused, from code review, I didn't see what will cause hdmi not work on rk3036 and rk3288,
>
> Give me some time, I try to bringup my popmetal rk3288 board to do the test.
>
> Heiko, Thanks very much for your test.

Hi Heiko

After fix null pointer problem, On rk3288 popmetal board, hdmi works good on my test, Can you double check it?

Thanks.

> > Heiko
> >
> > _______________________________________________
> > Linux-rockchip mailing list
> > Linux-rockchip@xxxxxxxxxxxxxxxxxxx
> > http://lists.infradead.org/mailman/listinfo/linux-rockchip


--
ïark Yao