From: Aaro Koskinen Subject: [PATCH v2] hw_random: omap3-rom-rng: convert timer to delayed work Date: Wed, 18 Nov 2015 21:59:01 +0200 Message-ID: <1447876741-24114-1-git-send-email-aaro.koskinen@iki.fi> Cc: Aaro Koskinen To: Matt Mackall , Herbert Xu , linux-crypto@vger.kernel.org, Sebastian Reichel , =?UTF-8?q?Pali=20Roh=C3=A1r?= , linux-omap@vger.kernel.org Return-path: Received: from emh04.mail.saunalahti.fi ([62.142.5.110]:32980 "EHLO emh04.mail.saunalahti.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753403AbbKRT7O (ORCPT ); Wed, 18 Nov 2015 14:59:14 -0500 Sender: linux-crypto-owner@vger.kernel.org List-ID: 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 Signed-off-by: Aaro Koskinen --- v2: Include workqueue.h instead of timer.h. drivers/char/hw_random/omap3-rom-rng.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/char/hw_random/omap3-rom-rng.c b/drivers/char/hw_random/omap3-rom-rng.c index a405cdc..8da14f1 100644 --- a/drivers/char/hw_random/omap3-rom-rng.c +++ b/drivers/char/hw_random/omap3-rom-rng.c @@ -17,7 +17,7 @@ #include #include #include -#include +#include #include #include #include @@ -29,11 +29,11 @@ /* param1: ptr, param2: count, param3: flag */ 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 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; @@ -51,7 +51,7 @@ static int omap3_rom_rng_get_random(void *buf, unsigned int count) u32 r; u32 ptr; - del_timer_sync(&idle_timer); + cancel_delayed_work_sync(&idle_work); if (rng_idle) { clk_prepare_enable(rng_clk); 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); 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) return -EINVAL; return 0; @@ -102,7 +102,7 @@ static int omap3_rom_rng_probe(struct platform_device *pdev) 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"); if (IS_ERR(rng_clk)) { 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) { + cancel_delayed_work_sync(&idle_work); hwrng_unregister(&omap3_rom_rng_ops); clk_disable_unprepare(rng_clk); return 0; -- 2.4.0