From 446e850c38d9092688df3f1e5d610f3bff2a4152 Mon Sep 17 00:00:00 2001 From: "Kumar, Mahesh" Date: Thu, 17 Aug 2017 19:15:25 +0530 Subject: [PATCH] drm/i915/glk: IPC linetime watermark workaround for GLK Git-commit: 446e850c38d9092688df3f1e5d610f3bff2a4152 Patch-mainline: v4.15-rc1 References: FATE#322643 bsc#1055900 IF IPC is enabled LINETIME_WM value should be half of calculated value line time = ROUNDDOWN(1/2 * Calculated Line Time) Earlier code was rounding-up the value, But updated Bspec says we should take the ROUNDDOWN. This patch corrects that as well. Signed-off-by: Mahesh Kumar Reviewed-by: Maarten Lankhorst Signed-off-by: Maarten Lankhorst Link: https://patchwork.freedesktop.org/patch/msgid/20170817134529.2839-5-mahesh1.kumar@intel.com Acked-by: Takashi Iwai --- drivers/gpu/drm/i915/intel_pm.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4613,9 +4613,10 @@ skl_compute_linetime_wm(struct intel_crt linetime_wm = fixed16_to_u32_round_up(mul_u32_fixed16(8, linetime_us)); - /* Display WA #1135: bxt. */ - if (IS_BROXTON(dev_priv) && dev_priv->ipc_enabled) - linetime_wm = DIV_ROUND_UP(linetime_wm, 2); + /* Display WA #1135: bxt:ALL GLK:ALL */ + if ((IS_BROXTON(dev_priv) || IS_GEMINILAKE(dev_priv)) && + dev_priv->ipc_enabled) + linetime_wm /= 2; return linetime_wm; }