This is a note to let you know that I've just added the patch titled clk: bcm2835: Protect sections updating shared registers to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: clk-bcm2835-protect-sections-updating-shared-registers.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 7997f3b2df751aab0b8e60149b226a32966c41ac Mon Sep 17 00:00:00 2001 From: Boris Brezillon <boris.brezillon@xxxxxxxxxxx> Date: Thu, 8 Feb 2018 14:43:36 +0100 Subject: clk: bcm2835: Protect sections updating shared registers 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 @@ -912,8 +912,10 @@ 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); @@ -997,9 +999,11 @@ 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); Patches currently in stable-queue which might be from boris.brezillon@xxxxxxxxxxx are queue-4.4/clk-bcm2835-protect-sections-updating-shared-registers.patch