drm/fb: fix FBIOGET/PUT_VSCREENINFO pixel clock handling

commit 5349ef3127c77075ff70b2014f17ae0fbcaaf199 upstream

When the framebuffer driver does not publish detailed timing information
for the current video mode, the correct value for the pixclock field is
zero, not -1.

Since pixclock is actually unsigned, the value -1 would be interpreted
as 4294967295 picoseconds (i.e., about 4 milliseconds) by
register_framebuffer() and userspace programs.

This patch allows X.org's fbdev driver to work.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Tested-by: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 1d30802e773e383492c03aeabb99e6a3ddd623f2..75a9b83fd7d305fbf1d62559965cb27808af2c90 100644 (file)
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -114,7 +114,7 @@ static int intelfb_check_var(struct fb_var_screeninfo *var,
        struct drm_framebuffer *fb = &intel_fb->base;
        int depth;
 
-       if (var->pixclock == -1 || !var->pixclock)
+       if (var->pixclock != 0)
                return -EINVAL;
 
        /* Need to resize the fb object !!! */
@@ -205,7 +205,7 @@ static int intelfb_set_par(struct fb_info *info)
 
        DRM_DEBUG("%d %d\n", var->xres, var->pixclock);
 
-       if (var->pixclock != -1) {
+       if (var->pixclock != 0) {
 
                DRM_ERROR("PIXEL CLOCK SET\n");
                return -EINVAL;
@@ -692,7 +692,7 @@ static int intelfb_multi_fb_probe_crtc(struct drm_device *dev, struct drm_crtc *
        par->crtc_count = 1;
 
        if (new_fb) {
-               info->var.pixclock = -1;
+               info->var.pixclock = 0;
                if (register_framebuffer(info) < 0)
                        return -EINVAL;
        } else
@@ -846,7 +846,7 @@ static int intelfb_single_fb_probe(struct drm_device *dev)
        par->crtc_count = crtc_count;
 
        if (new_fb) {
-               info->var.pixclock = -1;
+               info->var.pixclock = 0;
                if (register_framebuffer(info) < 0)
                        return -EINVAL;
        } else

diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c
index ec383edf5f38acb3370fb570a5553e792e45604f..f1d6d3d4519febe8e42448cfb62ed69c917dc35f 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_fb.c
+++ b/drivers/gpu/drm/radeon/radeon_fb.c
@@ -120,7 +120,7 @@ static int radeonfb_check_var(struct fb_var_screeninfo *var,
        struct drm_framebuffer *fb = &rfb->base;
        int depth;
 
-       if (var->pixclock == -1 || !var->pixclock) {
+       if (var->pixclock != 0) {
                return -EINVAL;
        }
        /* Need to resize the fb object !!! */
@@ -234,7 +234,7 @@ static int radeonfb_set_par(struct fb_info *info)
        int ret;
        int i;
 
-       if (var->pixclock != -1) {
+       if (var->pixclock != 0) {
                DRM_ERROR("PIXEL CLCOK SET\n");
                return -EINVAL;
        }
@@ -828,7 +828,7 @@ static int radeonfb_single_fb_probe(struct radeon_device *rdev)
        rfbdev->crtc_count = crtc_count;
 
        if (new_fb) {
-               info->var.pixclock = -1;
+               info->var.pixclock = 0;
                if (register_framebuffer(info) < 0)
                        return -EINVAL;
        } else {