Re: [Intel-gfx] [PATCH] drm/i915: mark expected switch fall-through

From: Gustavo A. R. Silva
Date: Wed Jun 20 2018 - 17:27:20 EST




On 06/20/2018 02:06 PM, Rodrigo Vivi wrote:
On Wed, Jun 20, 2018 at 08:31:00AM -0500, Gustavo A. R. Silva wrote:
In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Addresses-Coverity-ID: 1470102 ("Missing break in switch")

Any other advantage besides coverity?
Can't we address it by marking as "Intentional" on the tool?


Yes. The advantage of this is that it will eventually allows to enable -Wimplicit-fallthrough, hence, enabling the compiler to trigger a warning, which will force us to double check if we are actually missing a break before committing the code.

The change in the code has nothing to do with the Coverity tool. The tool is only reporting the issue, which, in this case, is a false positive.


I'm afraid there will be so many more places to add fallthrough
marks....


Oh yeah, there are around 1000 similar places in the whole codebase. There is an ongoing effort to review each case. Months ago, it used to be around 1500 of these cases.

Thanks
--
Gustavo

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_dpll_mgr.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/intel_dpll_mgr.c b/drivers/gpu/drm/i915/intel_dpll_mgr.c
index 132fe63..6a40a77 100644
--- a/drivers/gpu/drm/i915/intel_dpll_mgr.c
+++ b/drivers/gpu/drm/i915/intel_dpll_mgr.c
@@ -2566,6 +2566,7 @@ int icl_calc_dp_combo_pll_link(struct drm_i915_private *dev_priv,
switch (index) {
default:
MISSING_CASE(index);
+ /* fall through */
case 0:
link_clock = 540000;
break;
--
2.7.4

_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx