On Fri, Nov 12, 2021 at 02:28:30PM +0530, Jagan Teki wrote:
> On Fri, Nov 12, 2021 at 2:12 PM Michael Tretter wrote:
> > On Thu, 11 Nov 2021 13:21:03 -0800, Tim Harvey wrote:
> > > On Thu, Nov 11, 2021 at 2:19 AM Jagan Teki <ja...@amarulasolutions.com>
> > > wrote:
> > > > On Wed, Nov 10, 2021 at 11:58 PM Jagan Teki
> > > > <ja...@amarulasolutions.com> wrote:
> > > > > On Wed, Nov 10, 2021 at 2:24 AM Tim Harvey <thar...@gateworks.com>
> > > > > wrote:
> > > > > > On Tue, Nov 9, 2021 at 12:39 PM Marek Vasut <ma...@denx.de> wrote:
> > > > > > > On 11/9/21 8:35 PM, Adam Ford wrote:
> > > > > > >
> > > > > > > [...]
> > > > > > >
> > > > > > > >> diff --git a/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > > > > >> b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > > > > >> index 208a0ed840f4..195dcbff7058 100644
> > > > > > > >> --- a/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > > > > >> +++ b/arch/arm64/boot/dts/freescale/imx8mm.dtsi
> > > > > > > >> @@ -188,6 +188,12 @@
> > > > > > > >> clock-output-names = "clk_ext4";
> > > > > > > >> };
> > > > > > > >>
> > > > > > > >> + mipi_phy: mipi-video-phy {
> > > > > > > >> + compatible = "fsl,imx8mm-mipi-video-phy";
> > > > > > > >> + syscon = <&disp_blk_ctrl>;
> > > > > > > >> + #phy-cells = <1>;
> > > > > > > >> + };
> > > > > > > >> +
> > > > > > > >> psci {
> > > > > > > >> compatible = "arm,psci-1.0";
> > > > > > > >> method = "smc";
> > > > > > > >> @@ -1068,6 +1074,68 @@
> > > > > > > >> #size-cells = <1>;
> > > > > > > >> ranges = <0x32c00000 0x32c00000
> > > > > > > >> 0x400000>;
> > > > > > > >>
> > > > > > > >> + lcdif: lcdif@32e00000 {
> > > > > > > >> + #address-cells = <1>;
> > > > > > > >> + #size-cells = <0>;
> > > > > > > >> + compatible =
> > > > > > > >> "fsl,imx8mm-lcdif", "fsl,imx6sx-lcdif";
> > > > > > > >
> > > > > > > > The compatible "imx6sx-lcdif" implies MXSFB_V6. FWICT, it is
> > > > > > > > like
> > > > > > > > MXSFB_V4, but with overlays and those overlays have more
> > > > > > > > registers
> > > > > > > > configured in the mxsfb_kms driver. Have you tried using
> > > > > > > > imx28-lcdif
> > > > > > > > to see if it makes a difference?
> > > > > > >
> > > > > > > Indeed, MX6SX has AS overlay plane support, MX{2,}8 does not.
> > > > > > >
> > > > > > > LCDIFv3 (as NXP calls it) in MX8MP is like LCDIFv6 (in MX6SX) with
> > > > > > > slightly reordered register bits, but nothing like LCDIF rev3 (in
> > > > > > > MX23)
> > > > > > > ... just to make sure there is no confusion.
> > > > > > >
> > > > > > > [...]
> > > > > > >
> > > > > > > >> + mipi_dsi: mipi_dsi@32e10000 {
> > > > > > > >> + #address-cells = <1>;
> > > > > > > >> + #size-cells = <0>;
> > > > > > > >> + compatible =
> > > > > > > >> "fsl,imx8mm-mipi-dsim";
> > > > > > > >> + reg = <0x32e10000 0x400>;
> > > > > > > >> + clocks = <&clk
> > > > > > > >> IMX8MM_CLK_DSI_CORE>,
> > > > > > > >> + <&clk
> > > > > > > >> IMX8MM_CLK_DSI_PHY_REF>;
> > > > > > > >> + clock-names = "bus_clk",
> > > > > > > >> "sclk_mipi";
> > > > > > > >> + assigned-clocks = <&clk
> > > > > > > >> IMX8MM_CLK_DSI_CORE>,
> > > > > > > >> + <&clk
> > > > > > > >> IMX8MM_VIDEO_PLL1_OUT>,
> > > > > > > >> + <&clk
> > > > > > > >> IMX8MM_CLK_DSI_PHY_REF>;
> > > > > > > >> + assigned-clock-parents = <&clk
> > > > > > > >> IMX8MM_SYS_PLL1_266M>,
> > > > > > > >> + <&clk
> > > > > > > >> IMX8MM_VIDEO_PLL1_BYPASS>,
> > > > > > > >> + <&clk
> > > > > > > >> IMX8MM_VIDEO_PLL1_OUT>;
> > > > > > > >> + assigned-clock-rates =
> > > > > > > >> <266000000>, <594000000>, <27000000>;
> > > > > > > >> + interrupts = <GIC_SPI 18
> > > > > > > >> IRQ_TYPE_LEVEL_HIGH>;
> > > > > > > >> + phys = <&mipi_phy 0>;
> > > > > > > >> + phy-names = "dsim";
> > > > > > > >> + power-domains =
> > > > > > > >> <&disp_blk_ctrl IMX8MM_DISPBLK_PD_MIPI_DSI>;
> > > > > > > >> + samsung,burst-clock-frequency
> > > > > > > >> = <891000000>;
> > > > > > > >> + samsung,esc-clock-frequency =
> > > > > > > >> <54000000>;
> > > > > > > >> + samsung,pll-clock-frequency =
> > > > > > > >> <27000000>;
> > > > > > >
> > > > > > > This 27 MHz is really IMX8MM_CLK_DSI_PHY_REF and
> > > > > > > samsung,burst-clock-frequency is really the DSI link clock which
> > > > > > > is
> > > > > > > panel/bridge specific ... but, why do we need to specify such
> > > > > > > policy in
> > > > > > > DT rather than have the panel/bridge drivers negotiate the best
> > > > > > > clock
> > > > > > > settings with DSIM bridge driver ? This should be something which
> > > > > > > should
> > > > > > > be implemented in the DRM subsystem, not hard-coded in DT. These
> > > > > > > ad-hoc
> > > > > > > samsung,*-clock-frequency properties shouldn't even be needed
> > > > > > > then.
> > > > > > >
> > > > > > > Also, are the DSIM bindings stable now ?
> > > > > >
> > > > > > Thanks Marek.
> > > > > >
> > > > > > No, there is no dsim driver yet. I'm not clear if there is still
> > > > > > dissagreement on if the drm/exynos driver can be split up or if a
> > > > > > whole new somewhat duplicate driver needs to be made. I know Jagan
> > > > > > also has a series he is working on that uses drm/exynos which I
> > > > > > believe he will share an update on in a day or so.
> > > > > >
> > > > > > I'm still using the work that Michael [1] and you [2] did a long
> > > > > > time back.
> > > > > >
> > > > > > I had this solution working on a 5.10 kernel but it was based on the
> > > > > > old unapproved IMX8MM blk-ctl and pd drivers. Therefore I believe
> > > > > > the
> > > > > > issue I'm having is something not setup correctly with blk-ctl per
> > > > > > my
> > > > > > dt settings or perhaps something missing from the blk-ctl driver
> > > > > > like
> > > > > > Adam found [3]
> > > > > >
> > > > > > I am hanging at:
> > > > > > [ 1.064088] imx_pgc_power_up gpumix
> > > > > > [ 1.077506] imx_pgc_power_down gpumix
> > > > > > [ 1.097685] imx8m_blk_ctrl_power_on dispblk-mipi-dsi
> > > > > > [ 1.102682] imx_pgc_power_up dispmix
> > > > > > [ 1.106825] imx_pgc_power_up mipi
> > > > > > [ 1.110232] imx-dsim-dsi 32e10000.mipi_dsi: supply vddcore not
> > > > > > found, using dummy regulator
> > > > > > [ 1.118760] imx-dsim-dsi 32e10000.mipi_dsi: supply vddio not
> > > > > > found,
> > > > > > using dummy regulator
> > > > > > [ 1.127361] imx-dsim-dsi 32e10000.mipi_dsi: [drm] *ERROR*
> > > > > > modalias
> > > > > > failure on /soc@0/bus@32c00000/mipi_dsi@32e10000/port@0
> > > > > > [ 1.138676] imx8m_blk_ctrl_power_off dispblk-mipi-dsi
> > > > > > [ 1.143788] imx_pgc_power_down mipi
> > > > > > [ 1.145278] imx8m_blk_ctrl_power_on dispblk-lcdif
> > > > > > [ 1.147316] imx_pgc_power_down dispmix
> > > > > > [ 1.155804] imx_pgc_power_up dispmix
> > > > > > [ 1.159820] [drm:drm_bridge_attach] *ERROR* failed to attach
> > > > > > bridge
> > > > > > /soc@0/bus@32c00000/mipi_dsi@32e10000 to encoder None-34: -517
> > > > > > ^^^ this is just a defer
> > > > > > [ 1.171789] imx8m_blk_ctrl_power_off dispblk-lcdif
> > > > > > [ 1.176655] imx_pgc_power_down dispmix
> > > > > > [ 1.181790] libphy: fec_enet_mii_bus: probed
> > > > > > [ 3.915806] panel-simple panel: Expected bpc in {6,8} but got: 0
> > > > > > ^^^ not sure what this is but had it back in my 5.10 solution as
> > > > > > well
> > > > > > so did not investigate
> > > > > > [ 3.921912] imx8m_blk_ctrl_power_on dispblk-mipi-dsi
> > > > > > [ 3.926936] imx_pgc_power_up dispmix
> > > > > > [ 3.931109] imx_pgc_power_up mipi
> > > > > > [ 3.935409] imx8m_blk_ctrl_power_on dispblk-lcdif
> > > > > > [ 3.940547] imx8m_blk_ctrl_power_off dispblk-lcdif
> > > > > > [ 3.945626] [drm] Initialized mxsfb-drm 1.0.0 20160824 for
> > > > > > 32e00000.lcdif on minor 0
> > > > > > ^^^ not clear why dispblk-lcdif got disabled here
> > > > >
> > > > > I've reproduced this. look like lcdif power-domains are not notified
> > > > > ON. checking on the power-sequence for lcdif side. old patches from
> > > > > Lucas on v5.13 seems working as expected.
> > > >
> > > > I've found the issue on lcdif atomic_enable, where the bus format is
> > > > retrieved from NULL bus_state. Here is the diff for it.
> > > >
> > > > --- a/drivers/gpu/drm/mxsfb/mxsfb_kms.c
> > > > +++ b/drivers/gpu/drm/mxsfb/mxsfb_kms.c
> > > > @@ -359,13 +359,14 @@ static void mxsfb_crtc_atomic_enable(struct
> > > > drm_crtc *crtc,
> > > > drm_crtc_vblank_on(crtc);
> > > >
> > > > /* If there is a bridge attached to the LCDIF, use its bus
> > > > format */
> > > > - if (mxsfb->bridge) {
> > > > + if (mxsfb->bridge && state) {
> > > > bridge_state =
> > > > drm_atomic_get_new_bridge_state(state,
> > > > mxsfb->bridge);
> > > > - bus_format = bridge_state->input_bus_cfg.format;
> > > > + if (bridge_state)
> > > > + bus_format = bridge_state->input_bus_cfg.format;
> > > >'
> > > > I believe this can be fixed via DSIM bridge. working on for those
> > > > changes, the key challenges is to make the DSIM to work even for
> > > > exynos, which indeed blocker for me to validate in hardware (i don't
> > > > have DSI based exynos).
> > > >
> > > > Meanwhile, I have posed RFC for DSIM DTS changes, please check it here.
> > > > https://patchwork.kernel.org/project/dri-devel/cover/20211111101456.584061-1-ja...@amarulasolutions.com/
> > > >
> > >
> > > Jagan,
> > >
> > > Thank you! This does resolve the hang on my end as well. I will look
> > > at your 'arm64: imx8mm: Add MIPI DSI support' series.
> > >
> > > There was some discussion regarding giving up on trying to split up
> > > the exynos driver such that it could work with IMX8MM vs just
> > > duplicating it. I thought the recommendation was to duplicate it as it
> > > wasn't clear if there was a way to split it out without breaking
> > > current exynos DSI but I'll have to see if I can find the thread.
> >
> > The thread is here:
> >
> > https://lore.kernel.org/all/cakmk7uf0b1trtvx+9whasz49quha_is+77z2wx3c06bswri...@mail.gmail.com/
> >
> > Duplicating seems to be the best way forward, because the Exynos driver
> > exposes some special behavior (discussed earlier in the same thread), which
> > isn't compatible with how bridges work.
This seems to tbe the crux of the issue. I don't see what would be
specific to Exynos there, those issues should be fixed globally. If the
DRM bridge API can't support some use cases, it should be improved.
> Not quite sure about it. Laurent and Inki had similar discussion and
> looking for common bridge [1].
>
> [1]
> https://patchwork.kernel.org/project/linux-arm-kernel/patch/20210704090230.26489-7-ja...@amarulasolutions.com/
--
Regards,
Laurent Pinchart
