On Tue, 20 Aug 2024, Jouni Högander <jouni.hogander@xxxxxxxxx> wrote:
> In commit "drm/i915/display: Increase number of fast wake precharge pulses"
> we were increasing Fast Wake sync pulse length to fix problems observed on
> Dell Precision 5490 laptop with AUO panel. Later we have observed this is
> causing problems on other panels.
>
> Fix these problems by increasing Fast Wake sync pulse length as a quirk
> applied for Dell Precision 5490 with problematic panel.
>
> Fixes: f77772866385 ("drm/i915/display: Increase number of fast wake precharge pulses")
> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> Closes: http://gitlab.freedesktop.org/drm/i915/kernel/-/issues/9739
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2246
> Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11762
> Signed-off-by: Jouni Högander <jouni.hogander@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_alpm.c | 2 +-
> drivers/gpu/drm/i915/display/intel_dp_aux.c | 17 ++++++++++++-----
> drivers/gpu/drm/i915/display/intel_dp_aux.h | 2 +-
> drivers/gpu/drm/i915/display/intel_quirks.c | 9 +++++++++
> drivers/gpu/drm/i915/display/intel_quirks.h | 1 +
> 5 files changed, 24 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
> index 82ee778b2efe9..186cf4833f716 100644
> --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> @@ -228,7 +228,7 @@ bool intel_alpm_compute_params(struct intel_dp *intel_dp,
> int tfw_exit_latency = 20; /* eDP spec */
> int phy_wake = 4; /* eDP spec */
> int preamble = 8; /* eDP spec */
> - int precharge = intel_dp_aux_fw_sync_len() - preamble;
> + int precharge = intel_dp_aux_fw_sync_len(intel_dp) - preamble;
> u8 max_wake_lines;
>
> io_wake_time = max(precharge, io_buffer_wake_time(crtc_state)) +
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> index b8a53bb174dab..7adb1af252678 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> @@ -13,6 +13,7 @@
> #include "intel_dp_aux.h"
> #include "intel_dp_aux_regs.h"
> #include "intel_pps.h"
> +#include "intel_quirks.h"
> #include "intel_tc.h"
>
> #define AUX_CH_NAME_BUFSIZE 6
> @@ -142,16 +143,22 @@ static int intel_dp_aux_sync_len(void)
> return precharge + preamble;
> }
>
> -int intel_dp_aux_fw_sync_len(void)
> +int intel_dp_aux_fw_sync_len(struct intel_dp *intel_dp)
> {
> + int precharge = 10; /* 10-16 */
> + int preamble = 8;
> +
> /*
> * We faced some glitches on Dell Precision 5490 MTL laptop with panel:
> * "Manufacturer: AUO, Model: 63898" when using HW default 18. Using 20
> * is fixing these problems with the panel. It is still within range
> - * mentioned in eDP specification.
> + * mentioned in eDP specification. Increasing Fast Wake sync length is
> + * causing problems with other panels: increase length as a quirk for
> + * this specific laptop.
> */
> - int precharge = 12; /* 10-16 */
> - int preamble = 8;
> + if (intel_has_quirk(__intel_dp_to_intel_display(intel_dp),
Please don't use __intel_dp_to_intel_display() or *any* of the
__xxx_to_intel_display() directly. to_intel_display() is magic and
handles them all via _Generic().
Also add the local variable:
struct intel_display *display = to_intel_display(intel_dp);
Anyway, as I noted before, what if one sink has the issue, then it's
applied to all sinks here. Yeah it's unlikely with an eDP panel, but
let's not add such a mechanism. It should be sink specific, because we
may just end up having to do that anyway for some sinks.
> + QUIRK_FW_SYNC_LEN))
> + precharge += 2;
>
> return precharge + preamble;
> }
> @@ -211,7 +218,7 @@ static u32 skl_get_aux_send_ctl(struct intel_dp *intel_dp,
> DP_AUX_CH_CTL_TIME_OUT_MAX |
> DP_AUX_CH_CTL_RECEIVE_ERROR |
> DP_AUX_CH_CTL_MESSAGE_SIZE(send_bytes) |
> - DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(intel_dp_aux_fw_sync_len()) |
> + DP_AUX_CH_CTL_FW_SYNC_PULSE_SKL(intel_dp_aux_fw_sync_len(intel_dp)) |
> DP_AUX_CH_CTL_SYNC_PULSE_SKL(intel_dp_aux_sync_len());
>
> if (intel_tc_port_in_tbt_alt_mode(dig_port))
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.h b/drivers/gpu/drm/i915/display/intel_dp_aux.h
> index 76d1f2ed7c2f4..593f58fafab71 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.h
> @@ -20,6 +20,6 @@ enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder);
>
> void intel_dp_aux_irq_handler(struct drm_i915_private *i915);
> u32 intel_dp_aux_pack(const u8 *src, int src_bytes);
> -int intel_dp_aux_fw_sync_len(void);
> +int intel_dp_aux_fw_sync_len(struct intel_dp *intel_dp);
>
> #endif /* __INTEL_DP_AUX_H__ */
> diff --git a/drivers/gpu/drm/i915/display/intel_quirks.c b/drivers/gpu/drm/i915/display/intel_quirks.c
> index d9045b317cd16..acdd2ff1dd422 100644
> --- a/drivers/gpu/drm/i915/display/intel_quirks.c
> +++ b/drivers/gpu/drm/i915/display/intel_quirks.c
> @@ -65,6 +65,12 @@ static void quirk_no_pps_backlight_power_hook(struct intel_display *display)
> drm_info(display->drm, "Applying no pps backlight power quirk\n");
> }
>
> +static void quirk_fw_sync_len(struct intel_display *display)
> +{
> + intel_set_quirk(display, QUIRK_FW_SYNC_LEN);
> + drm_info(display->drm, "Applying Fast Wake sync pulse count quirk\n");
> +}
> +
> struct intel_quirk {
> int device;
> int subsystem_vendor;
> @@ -196,6 +202,9 @@ static struct intel_quirk intel_quirks[] = {
> /* Dell Chromebook 11 (2015 version) */
> { 0x0a16, 0x1028, 0x0a35, SINK_OUI_ANY, SINK_DEVICE_ID_ANY, quirk_backlight_present },
>
> + /* Dell Precision 5490 */
> + { 0x7d55, 0x1028, 0x0cc7, SINK_OUI(0x38, 0xec, 0x11), SINK_DEVICE_ID_ANY, quirk_fw_sync_len },
> +
> /* Toshiba Satellite P50-C-18C */
> { 0x191B, 0x1179, 0xF840, SINK_OUI_ANY, SINK_DEVICE_ID_ANY, quirk_increase_t12_delay },
>
> diff --git a/drivers/gpu/drm/i915/display/intel_quirks.h b/drivers/gpu/drm/i915/display/intel_quirks.h
> index 2d664af7e89f7..3c3e74310b7f2 100644
> --- a/drivers/gpu/drm/i915/display/intel_quirks.h
> +++ b/drivers/gpu/drm/i915/display/intel_quirks.h
> @@ -18,6 +18,7 @@ enum intel_quirk_id {
> QUIRK_INVERT_BRIGHTNESS,
> QUIRK_LVDS_SSC_DISABLE,
> QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK,
> + QUIRK_FW_SYNC_LEN,
> };
>
> void intel_init_quirks(struct intel_display *display);
--
Jani Nikula, Intel
