Commit 270c7a72 authored Nov 12, 2005 by Florin Malita Committed by Russell King Nov 12, 2005

[SERIAL] sa1100_start_tx spinlock recursion



The serial core aquires the port spinlock before calling
port->ops->start_tx(), so sa1100_start_tx() shouldn't try to lock it
again.

BUG: spinlock recursion on CPU#0, init/1
 lock: c0205f20, .magic: dead4ead, .owner: init/1, .owner_cpu: 0
[<c0022cdc>] (dump_stack+0x0/0x14) [<c00dc338>] (spin_bug+0x0/0xbc)
[<c00dc6b0>] (_raw_spin_lock+0x0/0x170)  r8 = 00000007  r7 = C02FE0070
[<c018a2a8>] (_spin_lock_irqsave+0x0/0x24)  r4 = C0205F20
[<c0112110>] (sa1100_start_tx+0x0/0x40)  r4 = C038C000
[<c010ee38>] (__uart_start+0x0/0x5c) [<c010ee94>] (uart_start+0x0/0x3
[<c010f1d0>] (uart_write+0x0/0xdc) [<c00fee34>] (write_chan+0x0/0x370

Signed-off-by: Florin Malita <fmalita@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

parent fa609435

drivers/serial/sa1100.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -156,7 +156,7 @@ static void sa1100_stop_tx(struct uart_port *port)
		}

		/*
		* interrupts may not be disabled on entry
		* port locked and interrupts disabled
		*/
		static void sa1100_start_tx(struct uart_port *port)
		{
		@@ -164,11 +164,9 @@ static void sa1100_start_tx(struct uart_port *port)
		unsigned long flags;
		u32 utcr3;

		spin_lock_irqsave(&sport->port.lock, flags);
		utcr3 = UART_GET_UTCR3(sport);
		sport->port.read_status_mask \|= UTSR0_TO_SM(UTSR0_TFS);
		UART_PUT_UTCR3(sport, utcr3 \| UTCR3_TIE);
		spin_unlock_irqrestore(&sport->port.lock, flags);
		}

		/*

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