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hwrng: omap3-rom - convert timer to delayed work

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We cannot put the HW RNG to idle using a timer because we cannot disable
clocks from atomic context. Use a delayed work instead.

Fixes a warning with CONFIG_DEBUG_MUTEXES on Nokia N900 during boot.

Reported-by: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Aaro Koskinen 2015-11-18 21:59:01 +02:00 committed by Herbert Xu
parent 56b85c9d7a
commit 4c13ac1cf0
1 changed files with 7 additions and 6 deletions
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13
drivers/char/hw_random/omap3-rom-rng.c
View file

@ -17,7 +17,7 @@
#include <linux/init.h> #include <linux/init.h>
#include <linux/random.h> #include <linux/random.h>
#include <linux/hw_random.h> #include <linux/hw_random.h>
#include <linux/timer.h> #include <linux/workqueue.h>
#include <linux/clk.h> #include <linux/clk.h>
#include <linux/err.h> #include <linux/err.h>
#include <linux/platform_device.h> #include <linux/platform_device.h>
@ -29,11 +29,11 @@
/* param1: ptr, param2: count, param3: flag */ /* param1: ptr, param2: count, param3: flag */
static u32 (*omap3_rom_rng_call)(u32, u32, u32); static u32 (*omap3_rom_rng_call)(u32, u32, u32);
static struct timer_list idle_timer; static struct delayed_work idle_work;
static int rng_idle; static int rng_idle;
static struct clk *rng_clk; static struct clk *rng_clk;
static void omap3_rom_rng_idle(unsigned long data) static void omap3_rom_rng_idle(struct work_struct *work)
{ {
int r; int r;
@ -51,7 +51,7 @@ static int omap3_rom_rng_get_random(void *buf, unsigned int count)
u32 r; u32 r;
u32 ptr; u32 ptr;
del_timer_sync(&idle_timer); cancel_delayed_work_sync(&idle_work);
if (rng_idle) { if (rng_idle) {
clk_prepare_enable(rng_clk); clk_prepare_enable(rng_clk);
r = omap3_rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT); r = omap3_rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT);
@ -65,7 +65,7 @@ static int omap3_rom_rng_get_random(void *buf, unsigned int count)
ptr = virt_to_phys(buf); ptr = virt_to_phys(buf);
r = omap3_rom_rng_call(ptr, count, RNG_GEN_HW); r = omap3_rom_rng_call(ptr, count, RNG_GEN_HW);
mod_timer(&idle_timer, jiffies + msecs_to_jiffies(500)); schedule_delayed_work(&idle_work, msecs_to_jiffies(500));
if (r != 0) if (r != 0)
return -EINVAL; return -EINVAL;
return 0; return 0;
@ -102,7 +102,7 @@ static int omap3_rom_rng_probe(struct platform_device *pdev)
return -EINVAL; return -EINVAL;
} }
setup_timer(&idle_timer, omap3_rom_rng_idle, 0); INIT_DELAYED_WORK(&idle_work, omap3_rom_rng_idle);
rng_clk = devm_clk_get(&pdev->dev, "ick"); rng_clk = devm_clk_get(&pdev->dev, "ick");
if (IS_ERR(rng_clk)) { if (IS_ERR(rng_clk)) {
pr_err("unable to get RNG clock\n"); pr_err("unable to get RNG clock\n");
@ -118,6 +118,7 @@ static int omap3_rom_rng_probe(struct platform_device *pdev)
static int omap3_rom_rng_remove(struct platform_device *pdev) static int omap3_rom_rng_remove(struct platform_device *pdev)
{ {
cancel_delayed_work_sync(&idle_work);
hwrng_unregister(&omap3_rom_rng_ops); hwrng_unregister(&omap3_rom_rng_ops);
clk_disable_unprepare(rng_clk); clk_disable_unprepare(rng_clk);
return 0; return 0;