ddr: fix overflow when ddr freq is high

PD#161475: ddr: fix overflow when ddr freq is high

Caculate of ddr freq will overflow if ddr freq is
over 1.5GHz, This commit fixed it.

Change-Id: Idc07b1022b52e3ec5c227c15afff1aaf21575ed7
Signed-off-by: tao zeng <tao.zeng@amlogic.com>

diff --git a/drivers/amlogic/ddr_tool/ddr_band_op_g12.c b/drivers/amlogic/ddr_tool/ddr_band_op_g12.c
index b791ec5..ec0f50f 100644 (file)
--- a/drivers/amlogic/ddr_tool/ddr_band_op_g12.c
+++ b/drivers/amlogic/ddr_tool/ddr_band_op_g12.c
@@ -97,8 +97,9 @@ static unsigned long g12_get_dmc_freq_quick(struct ddr_bandwidth *db)
        m = val & 0x1ff;
        n = ((val >> 10) & 0x1f);
        od1 = (((val >> 19) & 0x1)) == 1 ? 2 : 1;
+       freq = DEFAULT_XTAL_FREQ / 1000;        /* avoid overflow */
        if (n)
-               freq = (((DEFAULT_XTAL_FREQ * m) / n) >> od1) / od_div;
+               freq = ((((freq * m) / n) >> od1) / od_div) * 1000;
 
        return freq;
 }

diff --git a/drivers/amlogic/ddr_tool/ddr_band_op_gx.c b/drivers/amlogic/ddr_tool/ddr_band_op_gx.c
index 69dbc4e..387dd55 100644 (file)
--- a/drivers/amlogic/ddr_tool/ddr_band_op_gx.c
+++ b/drivers/amlogic/ddr_tool/ddr_band_op_gx.c
@@ -70,7 +70,8 @@ static unsigned long gx_get_dmc_freq_quick(struct ddr_bandwidth *db)
                    (db->cpu_type < MESON_CPU_MAJOR_ID_GXL)) {
                od1 = (val >> 14) & 0x03;
        }
-       freq = (DEFAULT_XTAL_FREQ * m / (n * (1 + od))) >> od1;
+       freq = DEFAULT_XTAL_FREQ / 1000;        /* avoid overflow */
+       freq = ((freq * m / (n * (1 + od))) >> od1) * 1000;
        return freq;
 }
 

diff --git a/drivers/amlogic/ddr_tool/ddr_band_op_gxl.c b/drivers/amlogic/ddr_tool/ddr_band_op_gxl.c
index 52ee4c2..6796f05 100644 (file)
--- a/drivers/amlogic/ddr_tool/ddr_band_op_gxl.c
+++ b/drivers/amlogic/ddr_tool/ddr_band_op_gxl.c
@@ -63,7 +63,8 @@ static unsigned long gxl_get_dmc_freq_quick(struct ddr_bandwidth *db)
        m    = (val >>  4) & 0x1ff;
        n    = (val >> 16) & 0x1f;
        od1  = (val >>  0) & 0x03;
-       freq = (DEFAULT_XTAL_FREQ * m / (n * (1 + od))) >> od1;
+       freq = DEFAULT_XTAL_FREQ / 1000;        /* avoid overflow */
+       freq = ((freq * m / (n * (1 + od))) >> od1) * 1000;
        return freq;
 }
 

diff --git a/include/linux/amlogic/aml_ddr_bandwidth.h b/include/linux/amlogic/aml_ddr_bandwidth.h
index e9efe9a..7982156 100644 (file)
--- a/include/linux/amlogic/aml_ddr_bandwidth.h
+++ b/include/linux/amlogic/aml_ddr_bandwidth.h
@@ -20,7 +20,7 @@
 
 
 #define DEFAULT_CLK_CNT                        12000000
-#define DEFAULT_XTAL_FREQ              24000000
+#define DEFAULT_XTAL_FREQ              24000000UL
 
 #define DMC_QOS_IRQ                    (1 << 30)
 #define MAX_CHANNEL                    4