Re: [v10,3/3] drm/rockchip: Add basic RK3588 HDMI output support

[Cristian Ciocaltea <cristian.ciocaltea@collabora.com>]

On 11/23/24 5:56 PM, Guenter Roeck wrote:
> On Wed, Oct 16, 2024 at 11:06:53PM +0300, Cristian Ciocaltea wrote:
>> The RK3588 SoC family integrates the newer Synopsys DesignWare HDMI 2.1
>> Quad-Pixel (QP) TX controller IP and a HDMI/eDP TX Combo PHY based on a
>> Samsung IP block.
>>
>> Add just the basic support for now, i.e. RGB output up to 4K@60Hz,
>> without audio, CEC or any of the HDMI 2.1 specific features.
>>
>> Co-developed-by: Algea Cao <algea.cao@rock-chips.com>
>> Signed-off-by: Algea Cao <algea.cao@rock-chips.com>
>> Tested-by: Heiko Stuebner <heiko@sntech.de>
>> Reviewed-by: Maxime Ripard <mripard@kernel.org>
>> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
>> ---
> [ ... ]
> 
>> +static void dw_hdmi_qp_rockchip_encoder_enable(struct drm_encoder *encoder)
>> +{
>> +	struct rockchip_hdmi_qp *hdmi = to_rockchip_hdmi_qp(encoder);
>> +	struct drm_crtc *crtc = encoder->crtc;
>> +	unsigned long long rate;
>> +
>> +	/* Unconditionally switch to TMDS as FRL is not yet supported */
>> +	gpiod_set_value(hdmi->enable_gpio, 1);
>> +
>> +	if (crtc && crtc->state) {
>> +		rate = drm_hdmi_compute_mode_clock(&crtc->state->adjusted_mode,
>> +						   8, HDMI_COLORSPACE_RGB);
>> +		clk_set_rate(hdmi->ref_clk, rate);
>> +		/*
>> +		 * FIXME: Temporary workaround to pass pixel clock rate
>> +		 * to the PHY driver until phy_configure_opts_hdmi
>> +		 * becomes available in the PHY API. See also the related
>> +		 * comment in rk_hdptx_phy_power_on() from
>> +		 * drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
>> +		 */
>> +		phy_set_bus_width(hdmi->phy, rate / 100);
> 
> On 32-bit systems:
> 
> ERROR: modpost: "__udivdi3" [drivers/gpu/drm/rockchip/rockchipdrm.ko] undefined!
> 
> in the mainline kernel.

Yeah, that's a known issue and has been already fixed:

https://lore.kernel.org/lkml/20241018151016.3496613-1-arnd@kernel.org/

Thanks,
Cristian