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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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e4fd17af61
According to i915 documentation [1], "Port D" (DP/HDMI Port D) is actually gmbus pin pair 6 (gmbus0.2:0 == 110b GPIOF), not 7 (111b). Pin pair 7 is a reserved pair. [1] Documentation for [DevSNB+] and [DevIBX], as found on http://intellinuxgraphics.org: [DevSNB+]: http://intellinuxgraphics.org/documentation/SNB/IHD_OS_Vol3_Part3.pdf Section 2.2.2 lists the 6 gmbus ports (gpio pin pairs): [ 5: HDMI/DPD, 4: HDMIB, 3: HDMI/DPC, 2: LVDS, 1: SSC, 0: VGA ] 2.2.2.1 lists the GPIO registers to control these 6 ports. 2.2.3.1 lists the mapping between 5 of these gmbus ports and the 3 Pin_Pair_Select bits (of the GMBUS0 register). This table is missing HDMIB (port 101). [DevIBX]: http://intellinuxgraphics.org/IHD_OS_Vol3_Part3r2.pdf Section 2.2.2 lists the same 6 gmbus ports plus two 'reserved' gpio ports. 2.2.2.1 lists 8 GPIO registers... however, it says the size of the block is 6x32, which implies that those 2 reserved GPIO registers (GPIO_6 & GPIO_7) don't actually exist (or are irrelevant). 2.2.3.1 lists the mapping between the 6 named gmbus ports and the 3 Pin_Pair_Select bits (of the GMBUS0 register). This table has HDMIB. Note: the "reserved" and "disabled" pairs do not actually map to a physical pair of pins, nor GPIO regs and shouldn't be initialized or used. Fixing this is left for a later patch. This bug had not been noticed earlier for two reasons: 1) Until recently, "gmbus" mode was disabled - all transfers actually used "bit-bang" mode on GPIO port 5 (the "HDMI/DPD CTLDATA/CLK" pair), at register 0x5024 (defined as GPIOF i915_reg.h). Since this is the correct pair of pins for HDMI1, transfers succeed. 2) Even if gmbus mode is re-enabled, the first attempted transaction will fail because it tries to use the wrong ("Reserved") pin pair. However, the driver immediately falls back again to the bit-bang method, which correctly uses GPIOF, so again, transfers succeed. However, if gmbus mode is re-enabled and the GPIO fall-back mode is disabled, then reading an attached monitor's EDID fail. Signed-off-by: Daniel Kurtz <djkurtz@chromium.org> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> |
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| .. | ||
| dvo_ch7xxx.c | ||
| dvo_ch7017.c | ||
| dvo_ivch.c | ||
| dvo_sil164.c | ||
| dvo_tfp410.c | ||
| dvo.h | ||
| i915_debugfs.c | ||
| i915_dma.c | ||
| i915_drv.c | ||
| i915_drv.h | ||
| i915_gem_debug.c | ||
| i915_gem_evict.c | ||
| i915_gem_execbuffer.c | ||
| i915_gem_gtt.c | ||
| i915_gem_tiling.c | ||
| i915_gem.c | ||
| i915_ioc32.c | ||
| i915_irq.c | ||
| i915_reg.h | ||
| i915_suspend.c | ||
| i915_trace_points.c | ||
| i915_trace.h | ||
| intel_acpi.c | ||
| intel_bios.c | ||
| intel_bios.h | ||
| intel_crt.c | ||
| intel_display.c | ||
| intel_dp.c | ||
| intel_drv.h | ||
| intel_dvo.c | ||
| intel_fb.c | ||
| intel_hdmi.c | ||
| intel_i2c.c | ||
| intel_lvds.c | ||
| intel_modes.c | ||
| intel_opregion.c | ||
| intel_overlay.c | ||
| intel_panel.c | ||
| intel_ringbuffer.c | ||
| intel_ringbuffer.h | ||
| intel_sdvo_regs.h | ||
| intel_sdvo.c | ||
| intel_sprite.c | ||
| intel_tv.c | ||
| Makefile | ||