From: Ingo Molnar floppy.c does alot of irq-unsafe work within floppy_release_irq_and_dma(): free_irq(), release_region() ... so when executing in irq context, push the whole function into keventd. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton --- drivers/block/floppy.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) diff -puN drivers/block/floppy.c~lock-validator-floppyc-irq-release-fix drivers/block/floppy.c --- devel/drivers/block/floppy.c~lock-validator-floppyc-irq-release-fix 2006-05-29 18:11:33.000000000 -0700 +++ devel-akpm/drivers/block/floppy.c 2006-05-29 18:11:33.000000000 -0700 @@ -573,6 +573,21 @@ static int floppy_grab_irq_and_dma(void) static void floppy_release_irq_and_dma(void); /* + * Interrupt, DMA and region freeing must not be done from IRQ + * context - e.g. irq-unregistration means /proc VFS work, region + * release takes an irq-unsafe lock, etc. So we push this work + * into keventd: + */ +static void fd_release_fn(void *data) +{ + mutex_lock(&open_lock); + floppy_release_irq_and_dma(); + mutex_unlock(&open_lock); +} + +static DECLARE_WORK(floppy_release_irq_and_dma_work, fd_release_fn, NULL); + +/* * The "reset" variable should be tested whenever an interrupt is scheduled, * after the commands have been sent. This is to ensure that the driver doesn't * get wedged when the interrupt doesn't come because of a failed command. @@ -836,7 +851,7 @@ static int set_dor(int fdc, char mask, c if (newdor & FLOPPY_MOTOR_MASK) floppy_grab_irq_and_dma(); if (olddor & FLOPPY_MOTOR_MASK) - floppy_release_irq_and_dma(); + schedule_work(&floppy_release_irq_and_dma_work); return olddor; } @@ -917,6 +932,8 @@ static int _lock_fdc(int drive, int inte set_current_state(TASK_RUNNING); remove_wait_queue(&fdc_wait, &wait); + + flush_scheduled_work(); } command_status = FD_COMMAND_NONE; @@ -950,7 +967,7 @@ static inline void unlock_fdc(void) if (elv_next_request(floppy_queue)) do_fd_request(floppy_queue); spin_unlock_irqrestore(&floppy_lock, flags); - floppy_release_irq_and_dma(); + schedule_work(&floppy_release_irq_and_dma_work); wake_up(&fdc_wait); } @@ -4647,6 +4664,12 @@ void cleanup_module(void) del_timer_sync(&fd_timer); blk_cleanup_queue(floppy_queue); + /* + * Wait for any asynchronous floppy_release_irq_and_dma() + * calls to finish first: + */ + flush_scheduled_work(); + if (usage_count) floppy_release_irq_and_dma(); _