linux-kernel - Re: [PATCH REPOST] TDA1997x: replace video detection routine

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Message-ID: <m3im12df1m.fsf@t19.piap.pl>
Date:   Thu, 22 Jul 2021 08:43:33 +0200
From:   Krzysztof Hałasa <khalasa@...p.pl>
To:     Hans Verkuil <hverkuil@...all.nl>
Cc:     Mauro Carvalho Chehab <mchehab@...nel.org>,
        linux-media@...r.kernel.org, lkml <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH REPOST] TDA1997x: replace video detection routine

Also, I have spotted an interesting loop condition in
drivers/media/v4l2-core/v4l2-dv-timings.c (dated 2013,
d1c65ad6a44b0ff79d2f0bf726fa6fd9248991f4).
It obviously works (unless the table grows to 600+ entries), but I guess
I should make it "standard", shouldn't I?

The first case is pretty normal:
@@ -159,10 +161,10 @@ int v4l2_enum_dv_timings_cap(struct v4l2_enum_dv_timings *t,
     u32 i, idx;
 
     memset(t->reserved, 0, sizeof(t->reserved));
-    for (i = idx = 0; i < ARRAY_SIZE(timings); i++) {
-        if (v4l2_dv_valid_timings(timings + i, cap) &&
+    for (i = idx = 0; v4l2_dv_timings_presets[i].bt.width; i++) {
+        if (v4l2_dv_valid_timings(v4l2_dv_timings_presets + i, cap) &&
             idx++ == t->index) {
-            t->timings = timings[i];
+            t->timings = v4l2_dv_timings_presets[i];
             return 0;
         }
     }

This is the interesting part:
@@ -179,10 +181,10 @@ bool v4l2_find_dv_timings_cap(struct v4l2_dv_timings *t,
     if (!v4l2_dv_valid_timings(t, cap))
         return false;
 
-    for (i = 0; i < ARRAY_SIZE(timings); i++) {
-        if (v4l2_dv_valid_timings(timings + i, cap) &&
-            v4l2_match_dv_timings(t, timings + i, pclock_delta)) {
-            *t = timings[i];
+    for (i = 0; i < v4l2_dv_timings_presets[i].bt.width; i++) {
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+        if (v4l2_dv_valid_timings(v4l2_dv_timings_presets + i, cap) &&
+            v4l2_match_dv_timings(t, v4l2_dv_timings_presets + i, pclock_delta)) {
+            *t = v4l2_dv_timings_presets[i];
             return true;
         }
     }

-- 
Krzysztof "Chris" Hałasa

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