ping On 2020/11/27 21:07, Xiaoming Ni wrote:
When CONFIG_MTD_XIP=y, local_irq_disable() is called in xip_disable(). To avoid sleep in interrupt context, we need to call local_irq_enable() before schedule().The problem call stack is as follows: bug1: do_write_oneword_retry() xip_disable() local_irq_disable() do_write_oneword_once() schedule() bug2: do_write_buffer() xip_disable() local_irq_disable() do_write_buffer_wait() schedule() bug3: do_erase_chip() xip_disable() local_irq_disable() schedule() bug4: do_erase_oneblock() xip_disable() local_irq_disable() schedule() Fixes: 02b15e343aee ("[MTD] XIP for AMD CFI flash.") Cc: sta...@vger.kernel.org # v2.6.13 Signed-off-by: Xiaoming Ni <nixiaom...@huawei.com> --- drivers/mtd/chips/cfi_cmdset_0002.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c index a1f3e1031c3d..12c3776f093a 100644 --- a/drivers/mtd/chips/cfi_cmdset_0002.c +++ b/drivers/mtd/chips/cfi_cmdset_0002.c @@ -1682,7 +1682,11 @@ static int __xipram do_write_oneword_once(struct map_info *map, set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); + if (IS_ENABLED(CONFIG_MTD_XIP)) + local_irq_enable(); schedule(); + if (IS_ENABLED(CONFIG_MTD_XIP)) + local_irq_disable(); remove_wait_queue(&chip->wq, &wait); timeo = jiffies + (HZ / 2); /* FIXME */ mutex_lock(&chip->mutex); @@ -1962,7 +1966,11 @@ static int __xipram do_write_buffer_wait(struct map_info *map, set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); + if (IS_ENABLED(CONFIG_MTD_XIP)) + local_irq_enable(); schedule(); + if (IS_ENABLED(CONFIG_MTD_XIP)) + local_irq_disable(); remove_wait_queue(&chip->wq, &wait); timeo = jiffies + (HZ / 2); /* FIXME */ mutex_lock(&chip->mutex); @@ -2461,7 +2469,11 @@ static int __xipram do_erase_chip(struct map_info *map, struct flchip *chip) set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); + if (IS_ENABLED(CONFIG_MTD_XIP)) + local_irq_enable(); schedule(); + if (IS_ENABLED(CONFIG_MTD_XIP)) + local_irq_disable(); remove_wait_queue(&chip->wq, &wait); mutex_lock(&chip->mutex); continue; @@ -2560,7 +2572,11 @@ static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip, set_current_state(TASK_UNINTERRUPTIBLE); add_wait_queue(&chip->wq, &wait); mutex_unlock(&chip->mutex); + if (IS_ENABLED(CONFIG_MTD_XIP)) + local_irq_enable(); schedule(); + if (IS_ENABLED(CONFIG_MTD_XIP)) + local_irq_disable(); remove_wait_queue(&chip->wq, &wait); mutex_lock(&chip->mutex); continue;
