Re: [PATCH RESEND 08/17] drm/spacemit: add Saturn DPU core types, cmdlist and display MMU

On Mon, 27 Jul 2026 09:35:35 +0200, Philipp Zabel wrote:
> On Sa, 2026-07-25 at 00:51 -0400, Cody Kang via B4 Relay wrote:
> > From: Cody Kang <[email protected]>
> >
> > Register programming of the Saturn DPU is batched: the driver builds
> > per-module register lists in memory and the hardware command-list
> > engine replays them at frame boundaries, while scanout buffers are
> > mapped through the DPU's private address translation unit (DMMU)
> > rather than scanned out by physical address.
> >
> > Add the shared driver types, the MMIO field accessors, the trace
> > events, the command-list builder and the DMMU table code. Some DPU
> > configuration registers are write-only, so a read-modify-write would
> > corrupt neighbouring fields; byte- and halfword-aligned fields are
> > therefore written at their native width instead.
> >
> > Signed-off-by: Cody Kang <[email protected]>
> > ---
> >  drivers/gpu/drm/spacemit/dpu/dpu_saturn.h   |  35 +++
> >  drivers/gpu/drm/spacemit/dpu/dpu_trace.h    | 350 ++++++++++++++++++++++++++++
> >  drivers/gpu/drm/spacemit/spacemit_cmdlist.c | 304 ++++++++++++++++++++++++
> >  drivers/gpu/drm/spacemit/spacemit_cmdlist.h | 146 ++++++++++++
> >  drivers/gpu/drm/spacemit/spacemit_crtc.h    | 259 ++++++++++++++++++++
> >  drivers/gpu/drm/spacemit/spacemit_dmmu.c    | 103 ++++++++
> >  drivers/gpu/drm/spacemit/spacemit_dmmu.h    |  40 ++++
> >  drivers/gpu/drm/spacemit/spacemit_dpu_reg.h | 108 +++++++++
> >  drivers/gpu/drm/spacemit/spacemit_drm.h     |  68 ++++++
> >  9 files changed, 1413 insertions(+)
> >
> [...]
> > diff --git a/drivers/gpu/drm/spacemit/spacemit_cmdlist.h b/drivers/gpu/drm/spacemit/spacemit_cmdlist.h
> > new file mode 100644
> > index 000000000000..d5acdbeb3b0e
> > --- /dev/null
> > +++ b/drivers/gpu/drm/spacemit/spacemit_cmdlist.h
> > @@ -0,0 +1,146 @@
> [...]
> > +struct spacemit_crtc {
> > +	struct device *dev;
> > +	struct drm_crtc crtc;
> > +	const struct dpu_core_ops *core;
> > +	struct dpu_mmu_tbl mmu_tbl;
> > +	int dev_id;
> > +	int irq_online;
> > +	struct timer_list cfg_rdy_timer;
> > +
> > +	bool is_1st_f;
> > +	bool first_modeset;
> > +	struct dpu_clk_context clk_ctx;
> > +	u32 aclk;
> > +	u32 out_format;
> > +
> > +	struct reset_control *mclk_reset;
> > +	struct reset_control *lcd_reset;
> > +	struct reset_control *esc_reset;
> > +	struct reset_control *aclk_reset;
> > +	struct reset_control *dsc_reset;
>
> Why are these duplicated from spacemit_drm_private?
> dpu_pm_suspend/resume() in patch 10 have access to priv.

You are right, they are plain 1:1 copies. Will drop the five
pointers from struct spacemit_crtc in v2; the reset sequencing in
spacemit_crtc.c and the suspend/resume paths will take them from
spacemit_drm_private instead.

Thanks for the review.

Cody