[media] lgdt3306a: don't go past the buffer

As warned by smatch:
	drivers/media/dvb-frontends/lgdt3306a.c:1354 log10_x1000() error: buffer overflow 'valx_x10' 14 <= 14
	drivers/media/dvb-frontends/lgdt3306a.c:1355 log10_x1000() error: buffer overflow 'log10x_x1000' 14 <= 14

There's a potential of returning a value out of the buffer. Fix it.

While here, remove the ugly braced block.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

diff --git a/drivers/media/dvb-frontends/lgdt3306a.c b/drivers/media/dvb-frontends/lgdt3306a.c
index c8af071ce40ba5c9b5fd8ae2955d2a47839e6163..92affe124a8d26188ead99c6dc911749e71ba8d3 100644 (file)
--- a/drivers/media/dvb-frontends/lgdt3306a.c
+++ b/drivers/media/dvb-frontends/lgdt3306a.c
@@ -1319,6 +1319,7 @@ static u32 log10_x1000(u32 x)
        static u32 valx_x10[]     = {  10,  11,  13,  15,  17,  20,  25,  33,  41,  50,  59,  73,  87,  100 };
        static u32 log10x_x1000[] = {   0,  41, 114, 176, 230, 301, 398, 518, 613, 699, 771, 863, 939, 1000 };
        static u32 nelems = sizeof(valx_x10)/sizeof(valx_x10[0]);
+       u32 diff_val, step_val, step_log10;
        u32 log_val = 0;
        u32 i;
 
@@ -1348,15 +1349,16 @@ static u32 log10_x1000(u32 x)
                if (valx_x10[i] >= x)
                        break;
        }
+       if (i == nelems)
+               return log_val + log10x_x1000[i - 1];
 
-       {
-               u32 diff_val   = x - valx_x10[i-1];
-               u32 step_val   = valx_x10[i] - valx_x10[i-1];
-               u32 step_log10 = log10x_x1000[i] - log10x_x1000[i-1];
-               /* do a linear interpolation to get in-between values */
-               return log_val + log10x_x1000[i-1] +
-                       ((diff_val*step_log10) / step_val);
-       }
+       diff_val   = x - valx_x10[i-1];
+       step_val   = valx_x10[i] - valx_x10[i - 1];
+       step_log10 = log10x_x1000[i] - log10x_x1000[i - 1];
+
+       /* do a linear interpolation to get in-between values */
+       return log_val + log10x_x1000[i - 1] +
+               ((diff_val*step_log10) / step_val);
 }
 
 static u32 lgdt3306a_calculate_snr_x100(struct lgdt3306a_state *state)