clk: bcm2835: add locking to pll*_on/off methods
authorMartin Sperl <kernel@martin.sperl.org>
Mon, 29 Feb 2016 11:39:18 +0000 (11:39 +0000)
committerEric Anholt <eric@anholt.net>
Thu, 17 Mar 2016 17:42:17 +0000 (10:42 -0700)
Add missing locking to:
* bcm2835_pll_divider_on
* bcm2835_pll_divider_off
to protect the read modify write cycle for the
register access protecting both cm_reg and a2w_reg
registers.

Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the
audio domain clocks")

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
drivers/clk/bcm/clk-bcm2835.c

index adbaa55..a39f8a7 100644 (file)
@@ -1085,10 +1085,12 @@ static void bcm2835_pll_divider_off(struct clk_hw *hw)
        struct bcm2835_cprman *cprman = divider->cprman;
        const struct bcm2835_pll_divider_data *data = divider->data;
 
+       spin_lock(&cprman->regs_lock);
        cprman_write(cprman, data->cm_reg,
                     (cprman_read(cprman, data->cm_reg) &
                      ~data->load_mask) | data->hold_mask);
        cprman_write(cprman, data->a2w_reg, A2W_PLL_CHANNEL_DISABLE);
+       spin_unlock(&cprman->regs_lock);
 }
 
 static int bcm2835_pll_divider_on(struct clk_hw *hw)
@@ -1097,12 +1099,14 @@ static int bcm2835_pll_divider_on(struct clk_hw *hw)
        struct bcm2835_cprman *cprman = divider->cprman;
        const struct bcm2835_pll_divider_data *data = divider->data;
 
+       spin_lock(&cprman->regs_lock);
        cprman_write(cprman, data->a2w_reg,
                     cprman_read(cprman, data->a2w_reg) &
                     ~A2W_PLL_CHANNEL_DISABLE);
 
        cprman_write(cprman, data->cm_reg,
                     cprman_read(cprman, data->cm_reg) & ~data->hold_mask);
+       spin_unlock(&cprman->regs_lock);
 
        return 0;
 }