From 2803aa743fd38f66acca555ae6e5fc677bb71251 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Sat, 16 May 2020 22:23:28 +0100 Subject: [PATCH] drm: Help unconfuse gcc, avoid accidental impossible unsigned comparisons MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit drivers/gpu/drm/drm_client_modeset.c: In function ‘drm_client_firmware_config’: ./include/linux/bits.h:26:28: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits] __builtin_constant_p((l) > (h)), (l) > (h), 0))) v2: Add a warning for passing connector_count==0 as this will hit an infinite loop, so document the invalid parameter. Signed-off-by: Chris Wilson Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20200516212330.13633-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/drm_client_modeset.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c index 7443114bd713..66e785b738eb 100644 --- a/drivers/gpu/drm/drm_client_modeset.c +++ b/drivers/gpu/drm/drm_client_modeset.c @@ -563,7 +563,7 @@ static bool drm_client_firmware_config(struct drm_client_dev *client, struct drm_client_offset *offsets, bool *enabled, int width, int height) { - unsigned int count = min_t(unsigned int, connector_count, BITS_PER_LONG); + const int count = min_t(unsigned int, connector_count, BITS_PER_LONG); unsigned long conn_configured, conn_seq, mask; struct drm_device *dev = client->dev; int i, j; @@ -577,6 +577,9 @@ static bool drm_client_firmware_config(struct drm_client_dev *client, if (!drm_drv_uses_atomic_modeset(dev)) return false; + if (WARN_ON(count <= 0)) + return false; + save_enabled = kcalloc(count, sizeof(bool), GFP_KERNEL); if (!save_enabled) return false;