linux-kernel - Re: [PATCH] drm/rockchip: dsi: Reset ISP1 DPHY before powering it on

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Message-ID: <pb477qi34clwdvrdrdparff5jvl6emdje3aswpylovejh2wx3q@vzwju366kkji>
Date: Wed, 17 Jul 2024 09:32:20 +0200
From: Ondřej Jirman <megi@....cz>
To: Dragan Simic <dsimic@...jaro.org>
Cc: linux-rockchip@...ts.infradead.org, dri-devel@...ts.freedesktop.org, 
	heiko@...ech.de, hjc@...k-chips.com, andy.yan@...k-chips.com, 
	maarten.lankhorst@...ux.intel.com, mripard@...nel.org, tzimmermann@...e.de, airlied@...il.com, 
	daniel@...ll.ch, linux-arm-kernel@...ts.infradead.org, 
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] drm/rockchip: dsi: Reset ISP1 DPHY before powering it on

On Wed, Jul 17, 2024 at 08:48:29AM GMT, Dragan Simic wrote:
> Hello all,
> 
> On 2024-07-17 08:29, Dragan Simic wrote:
> > From: Ondrej Jirman <megi@....cz>
> > 
> > After a suspend and resume cycle, ISP1 stops receiving data, as observed
> > on the Pine64 PinePhone Pro, which is based on the Rockchip RK3399 SoC.
> > Re-initializing DPHY during the PHY power-on, if the SoC variant
> > supports
> > initialization, fixes this issue.
> > 
> > [ dsimic: Added more details to the commit summary and description ]
> > 
> > Signed-off-by: Ondrej Jirman <megi@....cz>
> > Signed-off-by: Dragan Simic <dsimic@...jaro.org>
> > ---
> >  drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> > b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> > index 4cc8ed8f4fbd..9ad48c6dfac3 100644
> > --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> > +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c
> > @@ -1240,6 +1240,14 @@ static int dw_mipi_dsi_dphy_power_on(struct phy
> > *phy)
> >  		goto err_phy_cfg_clk;
> >  	}
> > 
> > +	if (dsi->cdata->dphy_rx_init) {
> > +		ret = dsi->cdata->dphy_rx_init(phy);
> > +		if (ret < 0) {
> > +			DRM_DEV_ERROR(dsi->dev, "hardware-specific phy init failed: %d\n",
> > ret);
> > +			goto err_pwr_on;
> > +		}
> > +	}
> > +
> >  	/* do soc-variant specific init */
> >  	if (dsi->cdata->dphy_rx_power_on) {
> >  		ret = dsi->cdata->dphy_rx_power_on(phy);
> 
> After thinking a bit more about this patch in its original form [1]
> that's preserved above, I think it would be better to move the
> additional DPHY initialization to dw_mipi_dsi_rockchip_resume(),
> because that function seems to be the right place for such fixes.
> 
> Please, let me know your thoughts.

That also works (see attachment) to fix the original issue in the commit
message, but if you keep the stream on across suspend/resume it does halt so
it's not a complete solution either.

Kind regards,
	o.

> [1] https://megous.com/git/linux/commit/?h=orange-pi-6.9&id=ed7992f668a1e529719ee6847ca114f9b67efacb

View attachment "0001-drm-rockchip-dw-mipi-dsi-rockchip-Restore-DPHY-confi.patch" of type "text/plain" (2659 bytes)