diff options
| -rw-r--r-- | drivers/clk/sunxi/clk-sunxi.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c index 692680d1b716..8135e311d38d 100644 --- a/drivers/clk/sunxi/clk-sunxi.c +++ b/drivers/clk/sunxi/clk-sunxi.c @@ -305,7 +305,7 @@ static void sun6i_a31_get_pll1_factors(u32 *freq, u32 parent_rate, const u8 f0[11] = {3, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0}; /* 2^3 * 3^1 */ const u8 N_max = 32; /* 5 bits */ const u8 K_max = 4; /* 2 bits */ - const u8 M_max = 4; /* 2 bits */ + u8 M_max = 4; /* 2 bits */ u8 N = 1, K = 1, M = 1; /* multiplicators (e.g. N = n+1) */ u32 freq_mhz, tmp; u8 success; @@ -314,6 +314,18 @@ static void sun6i_a31_get_pll1_factors(u32 *freq, u32 parent_rate, freq_mhz = *freq / 1000000; + /* Limit (24 MHz * (n+1) * (k+1)) to be less than 2.6 GHz + * This is caused by stability issues observed. + */ + if (freq_mhz <= 400) + M_max = 4; + else if (freq_mhz <= 800) + M_max = 3; + else if (freq_mhz <= 1200) + M_max = 2; + else + M_max = 1; + /* minimum possible frequency is 6 */ if (freq_mhz<6) freq_mhz = 6; |