[PATCH 4.9 11/67] clk: bcm2835: Protect sections updating shared registers

From: Greg Kroah-Hartman
Date: Tue Mar 27 2018 - 12:30:54 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>

commit 7997f3b2df751aab0b8e60149b226a32966c41ac upstream.

CM_PLLx and A2W_XOSC_CTRL registers are accessed by different clock
handlers and must be accessed with ->regs_lock held.
Update the sections where this protection is missing.

Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain clocks")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
Reviewed-by: Eric Anholt <eric@xxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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
@@ -566,8 +566,10 @@ static int bcm2835_pll_on(struct clk_hw
~A2W_PLL_CTRL_PWRDN);

/* Take the PLL out of reset. */
+ spin_lock(&cprman->regs_lock);
cprman_write(cprman, data->cm_ctrl_reg,
cprman_read(cprman, data->cm_ctrl_reg) & ~CM_PLL_ANARST);
+ spin_unlock(&cprman->regs_lock);

/* Wait for the PLL to lock. */
timeout = ktime_add_ns(ktime_get(), LOCK_TIMEOUT_NS);
@@ -644,9 +646,11 @@ static int bcm2835_pll_set_rate(struct c
}

/* Unmask the reference clock from the oscillator. */
+ spin_lock(&cprman->regs_lock);
cprman_write(cprman, A2W_XOSC_CTRL,
cprman_read(cprman, A2W_XOSC_CTRL) |
data->reference_enable_mask);
+ spin_unlock(&cprman->regs_lock);

if (do_ana_setup_first)
bcm2835_pll_write_ana(cprman, data->ana_reg_base, ana);