mirror of
https://github.com/torvalds/linux.git
synced 2026-10-30 14:06:03 +01:00
a9f09b5ea0
dw_hdmi_qp_set_sample_rate() open-coded its own N and CTS lookup tables and search/compute helpers, but it lacked the out-of-table CTS fallback needed by strict HDMI sinks at TMDS rates not in the table. The original LG G3 OLED audio mute (linux-rockchip 070633) was caused by dw_hdmi_qp_find_cts() returning 0 at 185.625 MHz, leaving AUDPKT_ACR_CTS_OVR_EN clear and falling back to the controller's internal CTS auto-measurement, which produces incorrect timing on the wire at out-of-table rates. The shared drm_hdmi_acr_get_n_cts() helper in drivers/gpu/drm/display/drm_hdmi_helper.c already implements the correct behaviour: it has the HDMI 1.4b spec N/CTS tables, and for TMDS rates not in the table it computes CTS = (TMDS * N) / (128 * Fs) inline (the canonical HDMI spec formula). It is already used by drivers/gpu/drm/msm/hdmi/hdmi_audio.c. Convert dw_hdmi_qp_set_sample_rate() to call the helper. This removes ~200 lines of open-coded tables and search functions (dw_hdmi_qp_find_n, _compute_n, _find_cts, _audio_math_diff, _match_tmds_n_table, common_tmds_n_table[], common_tmds_cts_table[]) and fixes the strict-sink audio mute as a side effect of using the helper's complete N+CTS path. Tested on R76S (RK3576) running Linux 7.0.1, against the LG G3 OLED (the sink that originally reported the mute in linux-rockchip 070633) at four TMDS rates spanning HDMI 1.4 and HDMI 2.0: TMDS Mode Audio with v3 148.5 MHz 1080p60 8-bit plays 185.625 MHz 1080p60 10-bit plays 297 MHz 1080p100 8-bit plays 594 MHz 3840p60 8-bit plays Without this change, the LG G3 mutes audio at 185.625, 297, and 594 MHz (every rate outside dw-hdmi-qp's open-coded CTS table, which contained only 148.5 MHz and below). With this change, drm_hdmi_acr_get_n_cts() supplies the correct CTS at every rate -- table-canonical at 148.5 / 297 / 594 MHz, and computed via the HDMI 1.4b formula at 185.625 MHz. The 148.5 MHz row is a regression check confirming the in-table path is unchanged. The Kogan KALED43XU9210STA (a permissive HDMI 2.0 sink that plays audio at all rates with or without this change) was used as a no-regression control: audio plays at 594 MHz with v3 loaded. The open-coded N table in dw-hdmi-qp included optimised N values for some TMDS rates that are not in the helper's table (e.g. various non-CEA rates between 28-162 MHz). For those rates the helper's fallback returns N = 128 * Fs / 1000, which is the same value dw_hdmi_qp_compute_n() returned when no table optimisation was needed; no audio regression has been observed at the rates tested above. Reported-by: Simon Wright <simon@symple.nz> Closes: https://lore.kernel.org/linux-rockchip/ME3P282MB21960D9D68BFF520316BDFCEA83E2@ME3P282MB2196.AUSP282.PROD.OUTLOOK.COM/ Suggested-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com> Suggested-by: Jonas Karlman <jonas@kwiboo.se> Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Simon Wright <simon@symple.nz> Tested-by: Igor Paunovic <royalnet026@gmail.com> # RK3588 Orange Pi 5 Plus, both HDMI controllers Tested-by: Christian Hewitt <christianshewitt@gmail.com> Reviewed-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com> Tested-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Link: https://patch.msgid.link/86fcf349-0a7a-4618-9001-612371b0f71b@symple.nz |
||
|---|---|---|
| .. | ||
| accel | ||
| accessibility | ||
| acpi | ||
| amba | ||
| android | ||
| ata | ||
| atm | ||
| auxdisplay | ||
| base | ||
| bcma | ||
| block | ||
| bluetooth | ||
| bus | ||
| cache | ||
| cdrom | ||
| cdx | ||
| char | ||
| clk | ||
| clocksource | ||
| comedi | ||
| connector | ||
| counter | ||
| cpufreq | ||
| cpuidle | ||
| crypto | ||
| cxl | ||
| dax | ||
| dca | ||
| devfreq | ||
| dibs | ||
| dio | ||
| dma | ||
| dma-buf | ||
| dpll | ||
| edac | ||
| eisa | ||
| extcon | ||
| firewire | ||
| firmware | ||
| fpga | ||
| fsi | ||
| fwctl | ||
| gnss | ||
| gpib | ||
| gpio | ||
| gpu | ||
| greybus | ||
| hid | ||
| hsi | ||
| hte | ||
| hv | ||
| hwmon | ||
| hwspinlock | ||
| hwtracing | ||
| i2c | ||
| i3c | ||
| idle | ||
| iio | ||
| infiniband | ||
| input | ||
| interconnect | ||
| iommu | ||
| ipack | ||
| irqchip | ||
| leds | ||
| macintosh | ||
| mailbox | ||
| mcb | ||
| md | ||
| media | ||
| memory | ||
| memstick | ||
| message | ||
| mfd | ||
| misc | ||
| mmc | ||
| most | ||
| mtd | ||
| mux | ||
| net | ||
| nfc | ||
| ntb | ||
| nubus | ||
| nvdimm | ||
| nvme | ||
| nvmem | ||
| of | ||
| opp | ||
| parisc | ||
| parport | ||
| pci | ||
| pcmcia | ||
| peci | ||
| perf | ||
| phy | ||
| pinctrl | ||
| platform | ||
| pmdomain | ||
| pnp | ||
| power | ||
| powercap | ||
| pps | ||
| ps3 | ||
| ptp | ||
| pwm | ||
| rapidio | ||
| ras | ||
| regulator | ||
| remoteproc | ||
| resctrl | ||
| reset | ||
| rpmsg | ||
| rtc | ||
| s390 | ||
| sbus | ||
| scsi | ||
| sh | ||
| siox | ||
| slimbus | ||
| soc | ||
| soundwire | ||
| spi | ||
| spmi | ||
| ssb | ||
| staging | ||
| target | ||
| tc | ||
| tee | ||
| thermal | ||
| thunderbolt | ||
| tty | ||
| ufs | ||
| uio | ||
| usb | ||
| vdpa | ||
| vfio | ||
| vhost | ||
| video | ||
| virt | ||
| virtio | ||
| w1 | ||
| watchdog | ||
| xen | ||
| zorro | ||
| Kconfig | ||
| Makefile | ||