From b49b927f16acee626c56a1af4ab4cb062f75b5df Mon Sep 17 00:00:00 2001 From: Roger Quadros Date: Mon, 9 May 2016 11:28:37 +0300 Subject: [PATCH] mfd: omap-usb-tll: Fix scheduling while atomic BUG We shouldn't be calling clk_prepare_enable()/clk_prepare_disable() in an atomic context. Fixes the following issue: [ 5.830970] ehci-omap: OMAP-EHCI Host Controller driver [ 5.830974] driver_register 'ehci-omap' [ 5.895849] driver_register 'wl1271_sdio' [ 5.896870] BUG: scheduling while atomic: udevd/994/0x00000002 [ 5.896876] 4 locks held by udevd/994: [ 5.896904] #0: (&dev->mutex){......}, at: [] __driver_attach+0x60/0xac [ 5.896923] #1: (&dev->mutex){......}, at: [] __driver_attach+0x70/0xac [ 5.896946] #2: (tll_lock){+.+...}, at: [] omap_tll_enable+0x2c/0xd0 [ 5.896966] #3: (prepare_lock){+.+...}, at: [] clk_prepare_lock+0x48/0xe0 [ 5.897042] Modules linked in: wlcore_sdio(+) ehci_omap(+) dwc3_omap snd_soc_ts3a225e leds_is31fl319x bq27xxx_battery_i2c tsc2007 bq27xxx_battery bq2429x_charger ina2xx tca8418_keypad as5013 leds_tca6507 twl6040_vibra gpio_twl6040 bmp085_i2c(+) palmas_gpadc usb3503 palmas_pwrbutton bmg160_i2c(+) bmp085 bma150(+) bmg160_core bmp280 input_polldev snd_soc_omap_mcbsp snd_soc_omap_mcpdm snd_soc_omap snd_pcm_dmaengine [ 5.897048] Preemption disabled at:[< (null)>] (null) [ 5.897051] [ 5.897059] CPU: 0 PID: 994 Comm: udevd Not tainted 4.6.0-rc5-letux+ #233 [ 5.897062] Hardware name: Generic OMAP5 (Flattened Device Tree) [ 5.897076] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [ 5.897087] [] (show_stack) from [] (dump_stack+0x88/0xc0) [ 5.897099] [] (dump_stack) from [] (__schedule_bug+0xac/0xd0) [ 5.897111] [] (__schedule_bug) from [] (__schedule+0x88/0x7e4) [ 5.897120] [] (__schedule) from [] (schedule+0x9c/0xc0) [ 5.897129] [] (schedule) from [] (schedule_preempt_disabled+0x14/0x20) [ 5.897140] [] (schedule_preempt_disabled) from [] (mutex_lock_nested+0x258/0x43c) [ 5.897150] [] (mutex_lock_nested) from [] (clk_prepare_lock+0x48/0xe0) [ 5.897160] [] (clk_prepare_lock) from [] (clk_prepare+0x10/0x28) [ 5.897169] [] (clk_prepare) from [] (omap_tll_enable+0x64/0xd0) [ 5.897180] [] (omap_tll_enable) from [] (usbhs_runtime_resume+0x18/0x17c) [ 5.897192] [] (usbhs_runtime_resume) from [] (pm_generic_runtime_resume+0x2c/0x40) [ 5.897202] [] (pm_generic_runtime_resume) from [] (__rpm_callback+0x38/0x68) [ 5.897210] [] (__rpm_callback) from [] (rpm_callback+0x70/0x88) [ 5.897218] [] (rpm_callback) from [] (rpm_resume+0x4ec/0x7ec) [ 5.897227] [] (rpm_resume) from [] (__pm_runtime_resume+0x4c/0x64) [ 5.897236] [] (__pm_runtime_resume) from [] (driver_probe_device+0x30/0x70) [ 5.897246] [] (driver_probe_device) from [] (__driver_attach+0x88/0xac) [ 5.897256] [] (__driver_attach) from [] (bus_for_each_dev+0x50/0x84) [ 5.897267] [] (bus_for_each_dev) from [] (bus_add_driver+0xcc/0x1e4) [ 5.897276] [] (bus_add_driver) from [] (driver_register+0xac/0xf4) [ 5.897286] [] (driver_register) from [] (do_one_initcall+0x100/0x1b8) [ 5.897296] [] (do_one_initcall) from [] (do_init_module+0x58/0x1c0) [ 5.897304] [] (do_init_module) from [] (SyS_finit_module+0x88/0x90) [ 5.897313] [] (SyS_finit_module) from [] (ret_fast_syscall+0x0/0x1c) [ 5.912697] ------------[ cut here ]------------ [ 5.912711] WARNING: CPU: 0 PID: 994 at kernel/sched/core.c:2996 _raw_spin_unlock+0x28/0x58 [ 5.912717] DEBUG_LOCKS_WARN_ON(val > preempt_count()) Cc: Reported-by: H. Nikolaus Schaller Tested-by: H. Nikolaus Schaller Signed-off-by: Roger Quadros Signed-off-by: Lee Jones --- drivers/mfd/omap-usb-tll.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c index b7b3e8ee64f2..c30290f33430 100644 --- a/drivers/mfd/omap-usb-tll.c +++ b/drivers/mfd/omap-usb-tll.c @@ -269,6 +269,8 @@ static int usbtll_omap_probe(struct platform_device *pdev) if (IS_ERR(tll->ch_clk[i])) dev_dbg(dev, "can't get clock : %s\n", clkname); + else + clk_prepare(tll->ch_clk[i]); } pm_runtime_put_sync(dev); @@ -301,9 +303,12 @@ static int usbtll_omap_remove(struct platform_device *pdev) tll_dev = NULL; spin_unlock(&tll_lock); - for (i = 0; i < tll->nch; i++) - if (!IS_ERR(tll->ch_clk[i])) + for (i = 0; i < tll->nch; i++) { + if (!IS_ERR(tll->ch_clk[i])) { + clk_unprepare(tll->ch_clk[i]); clk_put(tll->ch_clk[i]); + } + } pm_runtime_disable(&pdev->dev); return 0; @@ -420,7 +425,7 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata) if (IS_ERR(tll->ch_clk[i])) continue; - r = clk_prepare_enable(tll->ch_clk[i]); + r = clk_enable(tll->ch_clk[i]); if (r) { dev_err(tll_dev, "Error enabling ch %d clock: %d\n", i, r); @@ -448,7 +453,7 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata) for (i = 0; i < tll->nch; i++) { if (omap_usb_mode_needs_tll(pdata->port_mode[i])) { if (!IS_ERR(tll->ch_clk[i])) - clk_disable_unprepare(tll->ch_clk[i]); + clk_disable(tll->ch_clk[i]); } } -- 2.39.5