Rather than allowing any old mode through, then subsequently refusing unmatchable clock rates in atomic_check when it's too late to back out and pick a different mode, let's do that validation up-front where it will cause unsupported modes to be correctly pruned in the first place.
This also eliminates an issue whereby a perceived clock rate of 0 would cause atomic disable to fail and prevent the module from being unloaded.
Signed-off-by: Robin Murphy robin.murphy@arm.com ---
This supersedes my previous patch here: https://patchwork.freedesktop.org/patch/288553/ --- drivers/gpu/drm/arm/hdlcd_crtc.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/arm/hdlcd_crtc.c b/drivers/gpu/drm/arm/hdlcd_crtc.c index 0b2b62f8fa3c..ecac6fe0b213 100644 --- a/drivers/gpu/drm/arm/hdlcd_crtc.c +++ b/drivers/gpu/drm/arm/hdlcd_crtc.c @@ -186,20 +186,19 @@ static void hdlcd_crtc_atomic_disable(struct drm_crtc *crtc, clk_disable_unprepare(hdlcd->clk); }
-static int hdlcd_crtc_atomic_check(struct drm_crtc *crtc, - struct drm_crtc_state *state) +static enum drm_mode_status hdlcd_crtc_mode_valid(struct drm_crtc *crtc, + const struct drm_display_mode *mode) { struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc); - struct drm_display_mode *mode = &state->adjusted_mode; long rate, clk_rate = mode->clock * 1000;
rate = clk_round_rate(hdlcd->clk, clk_rate); if (rate != clk_rate) { /* clock required by mode not supported by hardware */ - return -EINVAL; + return MODE_NOCLOCK; }
- return 0; + return MODE_OK; }
static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc, @@ -220,7 +219,7 @@ static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc, }
static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = { - .atomic_check = hdlcd_crtc_atomic_check, + .mode_valid = hdlcd_crtc_mode_valid, .atomic_begin = hdlcd_crtc_atomic_begin, .atomic_enable = hdlcd_crtc_atomic_enable, .atomic_disable = hdlcd_crtc_atomic_disable,