[media] xc4000: fixed frequency error

The xc_get_frequency_error() function reported the frequency error
incorrectly. The data read from the hardware is a signed integer, in
15625 Hz units. The attached patch fixes the bug.

Signed-off-by: Istvan Varga <istvan_v@mailbox.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/media/common/tuners/xc4000.c b/drivers/media/common/tuners/xc4000.c
index be43a6dfac6c..f50dd6e713f7 100644
--- a/drivers/media/common/tuners/xc4000.c
+++ b/drivers/media/common/tuners/xc4000.c
@@ -417,8 +417,9 @@ static int xc_get_frequency_error(struct xc4000_priv *priv, u32 *freq_error_hz)
         if (result != XC_RESULT_SUCCESS)
                 return result;
 
-        tmp = (u32)regData;
-        (*freq_error_hz) = (tmp * 15625) / 1000;
+        tmp = (u32)regData & 0xFFFFU;
+        tmp = (tmp < 0x8000U ? tmp : 0x10000U - tmp);
+        (*freq_error_hz) = tmp * 15625;
         return result;
 }