From ea39a50d29c2974e428f5239e2d353fe02ab51aa Mon Sep 17 00:00:00 2001
From: Jocelyn Falempe <jfalempe@redhat.com>
Date: Wed, 4 May 2022 15:40:26 +0200
Subject: drm/mgag200: Warn once if trying to set start address on broken
hardware.
Git-commit: d2addf89c5abf4024574d42000313175c6e074fc
Patch-mainline: v6.0-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849
Some MGA200 hardware is broken and can't use a start address > 0.
v2: Warn if startaddr is not 0, and hw doesn't support it.
(instead of removing MGAG200_FLAG_HW_BUG_NO_STARTADD)
Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220504134026.283417-4-jfalempe@redhat.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/mgag200/mgag200_mode.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 294a53b95c61..dec744d0bee2 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -223,6 +223,9 @@ static void mgag200_set_startadd(struct mga_device *mdev,
startadd = offset / 8;
+ if (startadd > 0)
+ drm_WARN_ON_ONCE(dev, mdev->flags & MGAG200_FLAG_HW_BUG_NO_STARTADD);
+
/*
* Can't store addresses any higher than that, but we also
* don't have more than 16 MiB of memory, so it should be fine.
--
2.38.1