Hi Sam,
Please help! I tried to push the first two patches to drm-misc-fixes using dim push, but it pushed other things too besides these patches. I am sorry, don't know what went wrong.
Anitha
> -----Original Message-----
> From: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Sent: Wednesday, July 28, 2021 12:05 AM
> To: Chrisanthus, Anitha <anitha.chrisanthus@xxxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx; Dea, Edmund J
> <edmund.j.dea@xxxxxxxxx>
> Subject: Re: [PATCH 01/14] drm/kmb: Enable LCD DMA for low TVDDCV
>
> Hi Anitha,
> On Tue, Jul 27, 2021 at 05:31:13PM -0700, Anitha Chrisanthus wrote:
> > From: Edmund Dea <edmund.j.dea@xxxxxxxxx>
> >
> > There's an undocumented dependency between LCD layer enable bits [2-5]
> > and the AXI pipelined read enable bit [28] in the LCD_CONTROL register.
> > The proper order of operation is:
> >
> > 1) Clear AXI pipelined read enable bit
> > 2) Set LCD layers
> > 3) Set AXI pipelined read enable bit
> >
> > With this update, LCD can start DMA when TVDDCV is reduced down to
> 700mV.
> >
> > Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display")
> > Signed-off-by: Edmund Dea <edmund.j.dea@xxxxxxxxx>
> Patch is missing your s-o-b.
>
> > ---
> > drivers/gpu/drm/kmb/kmb_drv.c | 14 ++++++++++++++
> > drivers/gpu/drm/kmb/kmb_plane.c | 15 +++++++++++++--
> > 2 files changed, 27 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/kmb/kmb_drv.c
> b/drivers/gpu/drm/kmb/kmb_drv.c
> > index 96ea1a2c11dd..c0b1c6f99249 100644
> > --- a/drivers/gpu/drm/kmb/kmb_drv.c
> > +++ b/drivers/gpu/drm/kmb/kmb_drv.c
> > @@ -203,6 +203,7 @@ static irqreturn_t handle_lcd_irq(struct drm_device
> *dev)
> > unsigned long status, val, val1;
> > int plane_id, dma0_state, dma1_state;
> > struct kmb_drm_private *kmb = to_kmb(dev);
> > + u32 ctrl = 0;
> >
> > status = kmb_read_lcd(kmb, LCD_INT_STATUS);
> >
> > @@ -227,6 +228,19 @@ static irqreturn_t handle_lcd_irq(struct drm_device
> *dev)
> > kmb_clr_bitmask_lcd(kmb, LCD_CONTROL,
> > kmb-
> >plane_status[plane_id].ctrl);
> >
> > + ctrl = kmb_read_lcd(kmb, LCD_CONTROL);
> > + if (!(ctrl & (LCD_CTRL_VL1_ENABLE |
> > + LCD_CTRL_VL2_ENABLE |
> > + LCD_CTRL_GL1_ENABLE |
> > + LCD_CTRL_GL2_ENABLE))) {
> > + /* If no LCD layers are using DMA,
> > + * then disable DMA pipelined AXI read
> > + * transactions.
> > + */
> > + kmb_clr_bitmask_lcd(kmb,
> LCD_CONTROL,
> > +
> LCD_CTRL_PIPELINE_DMA);
> > + }
> > +
> This function could benefit from a few helper functions to avoid all the
> indent. But this is un-related to this patch.
>
> > kmb->plane_status[plane_id].disable = false;
> > }
> > }
> > diff --git a/drivers/gpu/drm/kmb/kmb_plane.c
> b/drivers/gpu/drm/kmb/kmb_plane.c
> > index d5b6195856d1..2888dd5dcc2c 100644
> > --- a/drivers/gpu/drm/kmb/kmb_plane.c
> > +++ b/drivers/gpu/drm/kmb/kmb_plane.c
> > @@ -427,8 +427,14 @@ static void kmb_plane_atomic_update(struct
> drm_plane *plane,
> >
> > kmb_set_bitmask_lcd(kmb, LCD_CONTROL, ctrl);
> >
> > - /* FIXME no doc on how to set output format,these values are
> > - * taken from the Myriadx tests
> > + /* Enable pipeline AXI read transactions for the DMA
> > + * after setting graphics layers. This must be done
> > + * in a separate write cycle.
> > + */
> > + kmb_set_bitmask_lcd(kmb, LCD_CONTROL,
> LCD_CTRL_PIPELINE_DMA);
> > +
> > + /* FIXME no doc on how to set output format,these values are taken
> ^ add space
> > + * from the Myriadx tests
> > */
> > out_format |= LCD_OUTF_FORMAT_RGB888;
> >
> > @@ -526,6 +532,11 @@ struct kmb_plane *kmb_plane_init(struct
> drm_device *drm)
> > plane->id = i;
> > }
> >
> > + /* Disable pipeline AXI read transactions for the DMA
> > + * prior to setting graphics layers
> > + */
> > + kmb_clr_bitmask_lcd(kmb, LCD_CONTROL,
> LCD_CTRL_PIPELINE_DMA);
> > +
> > return primary;
> > cleanup:
> > drmm_kfree(drm, plane);
>
> With the two nits fixed:
> Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
