From 7b2eb2fdd4b1dbb02b340fadc222d744319fcd2b Mon Sep 17 00:00:00 2001
From: Joel Stanley <joel@jms.id.au>
Date: Wed, 17 Nov 2021 09:01:45 +0800
Subject: drm/aspeed: Fix vga_pw sysfs output
Git-commit: b4a6aaeaf4aa79f23775f6688a7e8db3ee1c1303
Patch-mainline: v5.16-rc3
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
Before the drm driver had support for this file there was a driver that
exposed the contents of the vga password register to userspace. It would
present the entire register instead of interpreting it.
The drm implementation chose to mask of the lower bit, without explaining
why. This breaks the existing userspace, which is looking for 0xa8 in
the lower byte.
Change our implementation to expose the entire register.
Fixes: 696029eb36c0 ("drm/aspeed: Add sysfs for output settings")
Reported-by: Oskar Senft <osk@google.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Jeremy Kerr <jk@codeconstruct.com.au>
Tested-by: Oskar Senft <osk@google.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211117010145.297253-1-joel@jms.id.au
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/aspeed/aspeed_gfx_drv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
index b53fee6f1c17..65f172807a0d 100644
--- a/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
+++ b/drivers/gpu/drm/aspeed/aspeed_gfx_drv.c
@@ -291,7 +291,7 @@ vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf)
if (rc)
return rc;
- return sprintf(buf, "%u\n", reg & 1);
+ return sprintf(buf, "%u\n", reg);
}
static DEVICE_ATTR_RO(vga_pw);
--
2.38.1