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From 39c3c0d0a8d038a692b95cc13e7d6acf2d04cf14 Mon Sep 17 00:00:00 2001
From: Martin Sperl <kernel@martin.sperl.org>
Date: Mon, 29 Feb 2016 11:39:18 +0000
Subject: [PATCH 257/304] clk: bcm2835: add locking to pll*_on/off methods
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>
(cherry picked from commit ec36a5c6682fdd5328abf15c3c67281bed0241d7)
---
drivers/clk/bcm/clk-bcm2835.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1097,10 +1097,12 @@ static void bcm2835_pll_divider_off(stru
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)
@@ -1109,12 +1111,14 @@ static int bcm2835_pll_divider_on(struct
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;
}
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