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authorDmitry Eremin-Solenikov <dbaryshkov@gmail.com>2014-11-26 12:21:56 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-26 19:35:49 -0800
commit50d1e7d1077b276e8faa9eebf8b710edf31fdeea (patch)
tree9d48568af7d1ca155007019506b368576cc71e13 /drivers/tty/serial/pxa.c
parent48f5cde566201f987125ec783f40dc84b69ce300 (diff)
downloadop-kernel-dev-50d1e7d1077b276e8faa9eebf8b710edf31fdeea.zip
op-kernel-dev-50d1e7d1077b276e8faa9eebf8b710edf31fdeea.tar.gz
serial: pxa: hold port.lock when reporting modem line changes
Both uart_handle_dcd_change() and uart_handle_cts_change() require a port lock to be held and will emit a warning when lockdep is enabled. Held corresponding lock. This fixes the following warnings: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at drivers/tty/serial/serial_core.c:2760 uart_handle_dcd_change+0xc8/0xf8() Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 3.18.0-rc5+ #26 [<c000dff8>] (unwind_backtrace) from [<c000bc70>] (show_stack+0x10/0x14) [<c000bc70>] (show_stack) from [<c00192ac>] (warn_slowpath_common+0x6c/0x8c) [<c00192ac>] (warn_slowpath_common) from [<c00192e8>] (warn_slowpath_null+0x1c/0x24) [<c00192e8>] (warn_slowpath_null) from [<c0182984>] (uart_handle_dcd_change+0xc8/0xf8) [<c0182984>] (uart_handle_dcd_change) from [<c018625c>] (serial_pxa_irq+0x268/0x3b0) [<c018625c>] (serial_pxa_irq) from [<c004d0d4>] (handle_irq_event_percpu+0x50/0x16c) [<c004d0d4>] (handle_irq_event_percpu) from [<c004d22c>] (handle_irq_event+0x3c/0x5c) [<c004d22c>] (handle_irq_event) from [<c004f7d0>] (handle_level_irq+0x94/0x118) [<c004f7d0>] (handle_level_irq) from [<c004ca0c>] (generic_handle_irq+0x20/0x30) [<c004ca0c>] (generic_handle_irq) from [<c004cbe0>] (__handle_domain_irq+0x38/0x70) [<c004cbe0>] (__handle_domain_irq) from [<c00085c4>] (ichp_handle_irq+0x24/0x34) [<c00085c4>] (ichp_handle_irq) from [<c000c7e4>] (__irq_svc+0x44/0x54) Exception stack(0xc07c7f58 to 0xc07c7fa0) 7f40: 00000001 00000001 7f60: 00000000 20000013 c07c6000 00000000 00000000 c07ce0a4 c07d7798 00000000 7f80: c07e8fb8 0000004c 00000000 c07c7fa0 c0044798 c0009f20 20000013 ffffffff [<c000c7e4>] (__irq_svc) from [<c0009f20>] (arch_cpu_idle+0x28/0x38) [<c0009f20>] (arch_cpu_idle) from [<c003c974>] (cpu_startup_entry+0x1b8/0x220) [<c003c974>] (cpu_startup_entry) from [<c0338c54>] (start_kernel+0x39c/0x40c) ---[ end trace 4c1b7ae03f6d9d30 ]--- ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at drivers/tty/serial/serial_core.c:2791 uart_handle_cts_change+0xa0/0xdc() Modules linked in: CPU: 0 PID: 0 Comm: swapper Tainted: G W 3.18.0-rc5+ #26 [<c000dff8>] (unwind_backtrace) from [<c000bc70>] (show_stack+0x10/0x14) [<c000bc70>] (show_stack) from [<c00192ac>] (warn_slowpath_common+0x6c/0x8c) [<c00192ac>] (warn_slowpath_common) from [<c00192e8>] (warn_slowpath_null+0x1c/0x24) [<c00192e8>] (warn_slowpath_null) from [<c018528c>] (uart_handle_cts_change+0xa0/0xdc) [<c018528c>] (uart_handle_cts_change) from [<c018624c>] (serial_pxa_irq+0x258/0x3b0) [<c018624c>] (serial_pxa_irq) from [<c004d0d4>] (handle_irq_event_percpu+0x50/0x16c) [<c004d0d4>] (handle_irq_event_percpu) from [<c004d22c>] (handle_irq_event+0x3c/0x5c) [<c004d22c>] (handle_irq_event) from [<c004f7d0>] (handle_level_irq+0x94/0x118) [<c004f7d0>] (handle_level_irq) from [<c004ca0c>] (generic_handle_irq+0x20/0x30) [<c004ca0c>] (generic_handle_irq) from [<c004cbe0>] (__handle_domain_irq+0x38/0x70) [<c004cbe0>] (__handle_domain_irq) from [<c00085c4>] (ichp_handle_irq+0x24/0x34) [<c00085c4>] (ichp_handle_irq) from [<c000c7e4>] (__irq_svc+0x44/0x54) Exception stack(0xc07c7f58 to 0xc07c7fa0) 7f40: 00000001 00000001 7f60: 00000000 20000013 c07c6000 00000000 00000000 c07ce0a4 c07d7798 00000000 7f80: c07e8fb8 0000004c 00000000 c07c7fa0 c0044798 c0009f20 20000013 ffffffff [<c000c7e4>] (__irq_svc) from [<c0009f20>] (arch_cpu_idle+0x28/0x38) [<c0009f20>] (arch_cpu_idle) from [<c003c974>] (cpu_startup_entry+0x1b8/0x220) [<c003c974>] (cpu_startup_entry) from [<c0338c54>] (start_kernel+0x39c/0x40c) ---[ end trace 4c1b7ae03f6d9d31 ]--- Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Acked-by: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/pxa.c')
-rw-r--r--drivers/tty/serial/pxa.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
index 21b7d8b..7788d53 100644
--- a/drivers/tty/serial/pxa.c
+++ b/drivers/tty/serial/pxa.c
@@ -223,6 +223,7 @@ static void serial_pxa_start_tx(struct uart_port *port)
}
}
+/* should hold up->port.lock */
static inline void check_modem_status(struct uart_pxa_port *up)
{
int status;
@@ -255,12 +256,14 @@ static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
iir = serial_in(up, UART_IIR);
if (iir & UART_IIR_NO_INT)
return IRQ_NONE;
+ spin_lock(&up->port.lock);
lsr = serial_in(up, UART_LSR);
if (lsr & UART_LSR_DR)
receive_chars(up, &lsr);
check_modem_status(up);
if (lsr & UART_LSR_THRE)
transmit_chars(up);
+ spin_unlock(&up->port.lock);
return IRQ_HANDLED;
}
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