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From:   Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc:     Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 01/38] media: tda10086: cleanup symbol_rate setting logic
Date:   Wed,  2 Sep 2020 18:10:04 +0200
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The original logic had an integer to unsigned integer
conversion, plus a float-point math. While gcc should be
able to do the match at compile time, other compilers might
not do the same. Also, those produce the following warnings
with static code analyzers:

	drivers/media/dvb-frontends/tda10086.c:300 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:303 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:306 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:309 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:312 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:315 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:318 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:321 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:324 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.
	drivers/media/dvb-frontends/tda10086.c:327 tda10086_set_symbol_rate() warn: unsigned 'symbol_rate' is never less than zero.

Change the logic to declare the reference constant as unsigned
and to not use float point math.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
---
 drivers/media/dvb-frontends/tda10086.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/media/dvb-frontends/tda10086.c b/drivers/media/dvb-frontends/tda10086.c
index be6b40138f6e..cdcf97664bba 100644
--- a/drivers/media/dvb-frontends/tda10086.c
+++ b/drivers/media/dvb-frontends/tda10086.c
@@ -17,7 +17,7 @@
 #include <media/dvb_frontend.h>
 #include "tda10086.h"
 
-#define SACLK 96000000
+#define SACLK 96000000U
 
 struct tda10086_state {
 	struct i2c_adapter* i2c;
@@ -297,34 +297,34 @@ static int tda10086_set_symbol_rate(struct tda10086_state *state,
 	dprintk ("%s %i\n", __func__, symbol_rate);
 
 	/* setup the decimation and anti-aliasing filters.. */
-	if (symbol_rate < (u32) (SACLK * 0.0137)) {
+	if (symbol_rate < SACLK / 10000 * 137) {
 		dfn=4;
 		afs=1;
-	} else if (symbol_rate < (u32) (SACLK * 0.0208)) {
+	} else if (symbol_rate < SACLK / 10000 * 208) {
 		dfn=4;
 		afs=0;
-	} else if (symbol_rate < (u32) (SACLK * 0.0270)) {
+	} else if (symbol_rate < SACLK / 10000 * 270) {
 		dfn=3;
 		afs=1;
-	} else if (symbol_rate < (u32) (SACLK * 0.0416)) {
+	} else if (symbol_rate < SACLK / 10000 * 416) {
 		dfn=3;
 		afs=0;
-	} else if (symbol_rate < (u32) (SACLK * 0.0550)) {
+	} else if (symbol_rate < SACLK / 10000 * 550) {
 		dfn=2;
 		afs=1;
-	} else if (symbol_rate < (u32) (SACLK * 0.0833)) {
+	} else if (symbol_rate < SACLK / 10000 * 833) {
 		dfn=2;
 		afs=0;
-	} else if (symbol_rate < (u32) (SACLK * 0.1100)) {
+	} else if (symbol_rate < SACLK / 10000 * 1100) {
 		dfn=1;
 		afs=1;
-	} else if (symbol_rate < (u32) (SACLK * 0.1666)) {
+	} else if (symbol_rate < SACLK / 10000 * 1666) {
 		dfn=1;
 		afs=0;
-	} else if (symbol_rate < (u32) (SACLK * 0.2200)) {
+	} else if (symbol_rate < SACLK / 10000 * 2200) {
 		dfn=0;
 		afs=1;
-	} else if (symbol_rate < (u32) (SACLK * 0.3333)) {
+	} else if (symbol_rate < SACLK / 10000 * 3333) {
 		dfn=0;
 		afs=0;
 	} else {
-- 
2.26.2