drm_edp_backlight_supported(9)

💅 drm_edp_backlight_supported(9) 💅

okay so bestie, welcome to the Kernel API Manual — this one's about peeking at an eDP DPCD and being like "hiiii do u do VESA backlight??" 🎀

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✨ NAME ✨

drm_edp_backlight_supported — check an eDP DPCD for VESA backlight support 🦋

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🌸 SYNOPSIS 🌸

bool drm_edp_backlight_supported (const u8
       edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE] );

like, that's the whole vibe. it takes a const u8 array sized EDP_DISPLAY_CTL_CAP_SIZE and gives you back a bool. no cap. ✨

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🫶 ARGUMENTS 🫶

• edp_dpcd — the DPCD we're checking, bestie. that's it, that's the arg. it's literally just the DPCD to check 💖

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🧚 DESCRIPTION 🧚

okay so here's the tea ☕ — note that currently this function will return false for panels which support various DPCD backlight features but which require the brightness be set through PWM, and don't support setting the brightness level via the DPCD.

so like… those panels are lowkey doing their own thing and this function is not gonna hype them up. it says false. periodt. 💅

fr fr, don't come for this function if your panel is a PWM-only girlie — that's a documented currently, not a bug. 🙈

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👑 RETURN 👑

• true — if edp_dpcd indicates that VESA backlight controls are supported 🎉 slay!!
• false — otherwise 😭

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⭐ SEE ALSO ⭐

the whole friend group, in order, no one left out 💜:

• Kernel file ./include/drm/display/drm_dp_helper.h
• struct drm_dp_vsc_sdp(9)
• struct drm_dp_as_sdp(9)
• drm_dp_dsc_sink_supports_format(9)
• drm_dp_is_uhbr_rate(9)
• struct drm_dp_aux_msg(9)
• struct drm_dp_aux_cec(9)
• struct drm_dp_aux(9)
• drm_dp_dpcd_readb(9)
• drm_dp_dpcd_read_data(9)
• drm_dp_dpcd_write_data(9)
• drm_dp_dpcd_writeb(9)
• drm_dp_dpcd_read_byte(9)
• drm_dp_dpcd_write_byte(9)
• struct drm_dp_desc(9)
• enum drm_dp_quirk(9)
• drm_dp_has_quirk(9)
• struct drm_edp_backlight_info(9)
• struct drm_dp_phy_test_params(9)

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okay that's the whole page, ily, go check those DPCDs responsibly 💖✨

this lil masterpiece lives in ./include/drm/display, dropped October 2026, and it's all about drm_edp_backlight_supported(9) — mwah, bye bestie 🎀🦋