| Message ID | 20241210034223.1493522-1-xiaolei.wang@windriver.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] serial: imx: Use uart_port_lock_irq() instead of uart_port_lock() | expand |
Am Dienstag, dem 10.12.2024 um 11:42 +0800 schrieb Xiaolei Wang: > When executing 'ehco mem > /sys/power/state', the following > deadlock occurs. Since there is output during the serial > port entering the suspend process, the suspend will be > interrupted, resulting in the nesting of locks. Therefore, > use uart_port_lock_irq() instead of uart_port_unlock(). > > WARNING: inconsistent lock state > 6.12.0-rc2-00002-g3c199ed5bd64-dirty #23 Not tainted > -------------------------------- > inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. > sh/494 [HC0[0]:SC0[0]:HE1:SE1] takes: > c4db5850 (&port_lock_key){?.-.}-{3:3}, at: imx_uart_enable_wakeup+0x14/0x254 > {IN-HARDIRQ-W} state was registered at: > lock_acquire+0x104/0x348 > _raw_spin_lock+0x48/0x84 > imx_uart_int+0x14/0x4dc > __handle_irq_event_percpu+0xac/0x2fc > handle_irq_event_percpu+0xc/0x40 > handle_irq_event+0x38/0x8c > handle_fasteoi_irq+0xb4/0x1b8 > handle_irq_desc+0x1c/0x2c > gic_handle_irq+0x6c/0xa0 > generic_handle_arch_irq+0x2c/0x64 > call_with_stack+0x18/0x20 > __irq_svc+0x9c/0xbc > _raw_spin_unlock_irqrestore+0x2c/0x48 > uart_write+0xd8/0x3a0 > do_output_char+0x1a8/0x1e4 > n_tty_write+0x224/0x440 > file_tty_write.constprop.0+0x124/0x250 > do_iter_readv_writev+0x100/0x1e0 > vfs_writev+0xc4/0x448 > do_writev+0x68/0xf8 > ret_fast_syscall+0x0/0x1c > irq event stamp: 31593 > hardirqs last enabled at (31593): [<c1150e48>] _raw_spin_unlock_irqrestore+0x44/0x48 > hardirqs last disabled at (31592): [<c07f32f0>] clk_enable_lock+0x60/0x120 > softirqs last enabled at (30334): [<c012d1d4>] handle_softirqs+0x2cc/0x478 > softirqs last disabled at (30325): [<c012d510>] __irq_exit_rcu+0x120/0x15c > > other info that might help us debug this: > Possible unsafe locking scenario: > > CPU0 > ---- > lock(&port_lock_key); > <Interrupt> > lock(&port_lock_key); > > Fixes: 3c199ed5bd64 ("serial: imx: Grab port lock in imx_uart_enable_wakeup()") > Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> Reviewed-by: Lucas Stach <l.stach@pengutronix.de> > --- > > v1: > https://patchwork.kernel.org/project/linux-arm-kernel/patch/20241209124732.693834-1-xiaolei.wang@windriver.com/ > v2: > use uart_port_lock_irq() instead of uart_port_lock_irqsave() > > drivers/tty/serial/imx.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c > index 17f70e4bee43..9c59ec128bb4 100644 > --- a/drivers/tty/serial/imx.c > +++ b/drivers/tty/serial/imx.c > @@ -2692,7 +2692,7 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) > { > u32 ucr3; > > - uart_port_lock(&sport->port); > + uart_port_lock_irq(&sport->port); > > ucr3 = imx_uart_readl(sport, UCR3); > if (on) { > @@ -2714,7 +2714,7 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) > imx_uart_writel(sport, ucr1, UCR1); > } > > - uart_port_unlock(&sport->port); > + uart_port_unlock_irq(&sport->port); > } > > static int imx_uart_suspend_noirq(struct device *dev)
On Tue, Dec 10, 2024 at 12:43 AM Xiaolei Wang <xiaolei.wang@windriver.com> wrote: > > When executing 'ehco mem > /sys/power/state', the following ehco --> echo Reviewed-by: Fabio Estevam <festevam@gmail.com>
On 12/10/24 9:37 PM, Fabio Estevam wrote: > CAUTION: This email comes from a non Wind River email account! > Do not click links or open attachments unless you recognize the sender and know the content is safe. > > On Tue, Dec 10, 2024 at 12:43 AM Xiaolei Wang > <xiaolei.wang@windriver.com> wrote: >> When executing 'ehco mem > /sys/power/state', the following > ehco --> echo Thanks, I will update the commit log in the next version thanks xiaolei > > Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 17f70e4bee43..9c59ec128bb4 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2692,7 +2692,7 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) { u32 ucr3; - uart_port_lock(&sport->port); + uart_port_lock_irq(&sport->port); ucr3 = imx_uart_readl(sport, UCR3); if (on) { @@ -2714,7 +2714,7 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on) imx_uart_writel(sport, ucr1, UCR1); } - uart_port_unlock(&sport->port); + uart_port_unlock_irq(&sport->port); } static int imx_uart_suspend_noirq(struct device *dev)
When executing 'ehco mem > /sys/power/state', the following deadlock occurs. Since there is output during the serial port entering the suspend process, the suspend will be interrupted, resulting in the nesting of locks. Therefore, use uart_port_lock_irq() instead of uart_port_unlock(). WARNING: inconsistent lock state 6.12.0-rc2-00002-g3c199ed5bd64-dirty #23 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. sh/494 [HC0[0]:SC0[0]:HE1:SE1] takes: c4db5850 (&port_lock_key){?.-.}-{3:3}, at: imx_uart_enable_wakeup+0x14/0x254 {IN-HARDIRQ-W} state was registered at: lock_acquire+0x104/0x348 _raw_spin_lock+0x48/0x84 imx_uart_int+0x14/0x4dc __handle_irq_event_percpu+0xac/0x2fc handle_irq_event_percpu+0xc/0x40 handle_irq_event+0x38/0x8c handle_fasteoi_irq+0xb4/0x1b8 handle_irq_desc+0x1c/0x2c gic_handle_irq+0x6c/0xa0 generic_handle_arch_irq+0x2c/0x64 call_with_stack+0x18/0x20 __irq_svc+0x9c/0xbc _raw_spin_unlock_irqrestore+0x2c/0x48 uart_write+0xd8/0x3a0 do_output_char+0x1a8/0x1e4 n_tty_write+0x224/0x440 file_tty_write.constprop.0+0x124/0x250 do_iter_readv_writev+0x100/0x1e0 vfs_writev+0xc4/0x448 do_writev+0x68/0xf8 ret_fast_syscall+0x0/0x1c irq event stamp: 31593 hardirqs last enabled at (31593): [<c1150e48>] _raw_spin_unlock_irqrestore+0x44/0x48 hardirqs last disabled at (31592): [<c07f32f0>] clk_enable_lock+0x60/0x120 softirqs last enabled at (30334): [<c012d1d4>] handle_softirqs+0x2cc/0x478 softirqs last disabled at (30325): [<c012d510>] __irq_exit_rcu+0x120/0x15c other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&port_lock_key); <Interrupt> lock(&port_lock_key); Fixes: 3c199ed5bd64 ("serial: imx: Grab port lock in imx_uart_enable_wakeup()") Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> --- v1: https://patchwork.kernel.org/project/linux-arm-kernel/patch/20241209124732.693834-1-xiaolei.wang@windriver.com/ v2: use uart_port_lock_irq() instead of uart_port_lock_irqsave() drivers/tty/serial/imx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)