diff options
author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2015-09-17 00:47:39 +0300 |
---|---|---|
committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-02-17 19:52:59 +0300 |
commit | 99a81706526fb167029a940ef1f7bfbe882abd3e (patch) | |
tree | f35afa9e90b6a0825bf3f527160482fda286e91c /drivers/clk/at91/clk-pll.c | |
parent | 1bdf02326b71eae7e9b4b335b881856aaf9d1af6 (diff) | |
download | linux-99a81706526fb167029a940ef1f7bfbe882abd3e.tar.xz |
clk: at91: remove IRQ handling and use polling
The AT91 clock drivers make use of IRQs to avoid polling when waiting for
some clocks to be enabled. Unfortunately, this leads to a crash when those
IRQs are threaded (which happens when using preempt-rt) because they are
registered before thread creation is possible.
Use polling on those clocks instead to avoid the problem.
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/clk/at91/clk-pll.c')
-rw-r--r-- | drivers/clk/at91/clk-pll.c | 47 |
1 files changed, 4 insertions, 43 deletions
diff --git a/drivers/clk/at91/clk-pll.c b/drivers/clk/at91/clk-pll.c index 5f4c6ce628e0..fb2e0b56d4b7 100644 --- a/drivers/clk/at91/clk-pll.c +++ b/drivers/clk/at91/clk-pll.c @@ -12,14 +12,6 @@ #include <linux/clkdev.h> #include <linux/clk/at91_pmc.h> #include <linux/of.h> -#include <linux/of_address.h> -#include <linux/of_irq.h> -#include <linux/io.h> -#include <linux/kernel.h> -#include <linux/wait.h> -#include <linux/sched.h> -#include <linux/interrupt.h> -#include <linux/irq.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> @@ -61,8 +53,6 @@ struct clk_pll_layout { struct clk_pll { struct clk_hw hw; struct regmap *regmap; - unsigned int irq; - wait_queue_head_t wait; u8 id; u8 div; u8 range; @@ -71,16 +61,6 @@ struct clk_pll { const struct clk_pll_characteristics *characteristics; }; -static irqreturn_t clk_pll_irq_handler(int irq, void *dev_id) -{ - struct clk_pll *pll = (struct clk_pll *)dev_id; - - wake_up(&pll->wait); - disable_irq_nosync(pll->irq); - - return IRQ_HANDLED; -} - static inline bool clk_pll_ready(struct regmap *regmap, int id) { unsigned int status; @@ -127,11 +107,8 @@ static int clk_pll_prepare(struct clk_hw *hw) (out << PLL_OUT_SHIFT) | ((pll->mul & layout->mul_mask) << layout->mul_shift)); - while (!clk_pll_ready(regmap, pll->id)) { - enable_irq(pll->irq); - wait_event(pll->wait, - clk_pll_ready(regmap, pll->id)); - } + while (!clk_pll_ready(regmap, pll->id)) + cpu_relax(); return 0; } @@ -320,7 +297,7 @@ static const struct clk_ops pll_ops = { }; static struct clk * __init -at91_clk_register_pll(struct regmap *regmap, unsigned int irq, const char *name, +at91_clk_register_pll(struct regmap *regmap, const char *name, const char *parent_name, u8 id, const struct clk_pll_layout *layout, const struct clk_pll_characteristics *characteristics) @@ -328,7 +305,6 @@ at91_clk_register_pll(struct regmap *regmap, unsigned int irq, const char *name, struct clk_pll *pll; struct clk *clk = NULL; struct clk_init_data init; - int ret; int offset = PLL_REG(id); unsigned int pllr; @@ -350,22 +326,12 @@ at91_clk_register_pll(struct regmap *regmap, unsigned int irq, const char *name, pll->layout = layout; pll->characteristics = characteristics; pll->regmap = regmap; - pll->irq = irq; regmap_read(regmap, offset, &pllr); pll->div = PLL_DIV(pllr); pll->mul = PLL_MUL(pllr, layout); - init_waitqueue_head(&pll->wait); - irq_set_status_flags(pll->irq, IRQ_NOAUTOEN); - ret = request_irq(pll->irq, clk_pll_irq_handler, IRQF_TRIGGER_HIGH, - id ? "clk-pllb" : "clk-plla", pll); - if (ret) { - kfree(pll); - return ERR_PTR(ret); - } clk = clk_register(NULL, &pll->hw); if (IS_ERR(clk)) { - free_irq(pll->irq, pll); kfree(pll); } @@ -499,7 +465,6 @@ of_at91_clk_pll_setup(struct device_node *np, const struct clk_pll_layout *layout) { u32 id; - unsigned int irq; struct clk *clk; struct regmap *regmap; const char *parent_name; @@ -521,11 +486,7 @@ of_at91_clk_pll_setup(struct device_node *np, if (!characteristics) return; - irq = irq_of_parse_and_map(np, 0); - if (!irq) - return; - - clk = at91_clk_register_pll(regmap, irq, name, parent_name, id, layout, + clk = at91_clk_register_pll(regmap, name, parent_name, id, layout, characteristics); if (IS_ERR(clk)) goto out_free_characteristics; |