From: Anson Huang Date: Tue, 6 Mar 2012 04:00:16 +0000 (+0800) Subject: ENGR00176160 [MX6]Correct PLL1 freq change flow X-Git-Tag: v3.0.35-fsl_4.1.0~1515 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=0319838b6e96cf7db91a9f8faee18fbf024068e4;p=karo-tx-linux.git ENGR00176160 [MX6]Correct PLL1 freq change flow Previous PLL1 freq change is done by switching CPU clock to 400M pfd or 24M OSC, then modifying PLL1 div directly, and switch back CPU clock immediately, it will result in CPU clock stop during PLL1 hardware lock period, thus, DRAM FIFO may blocked by the data CPU requested before PLL1 clock changed, and it will block other devices accessing DRAM, such as IPU, VPU etc. It will cause underrun or hang issue. We should wait PLL1 lock, then switch back. Signed-off-by: Anson Huang --- diff --git a/arch/arm/mach-mx6/clock.c b/arch/arm/mach-mx6/clock.c index 89d4810e4376..2ab6cb9daf4a 100644 --- a/arch/arm/mach-mx6/clock.c +++ b/arch/arm/mach-mx6/clock.c @@ -492,17 +492,23 @@ static unsigned long _clk_pll1_main_get_rate(struct clk *clk) static int _clk_pll1_main_set_rate(struct clk *clk, unsigned long rate) { - unsigned int reg, div; + unsigned int reg, div; if (rate < AUDIO_VIDEO_MIN_CLK_FREQ || rate > AUDIO_VIDEO_MAX_CLK_FREQ) return -EINVAL; - div = (rate * 2) / clk_get_rate(clk->parent) ; + div = (rate * 2) / clk_get_rate(clk->parent); + /* Update div */ reg = __raw_readl(PLL1_SYS_BASE_ADDR) & ~ANADIG_PLL_SYS_DIV_SELECT_MASK; reg |= div; __raw_writel(reg, PLL1_SYS_BASE_ADDR); + /* Wait for PLL1 to lock */ + if (!WAIT(__raw_readl(PLL1_SYS_BASE_ADDR) & ANADIG_PLL_LOCK, + SPIN_DELAY)) + panic("pll1 enable failed\n"); + return 0; }