From dc1972d02747d2170fb1d78d114801f5ecb27506 Mon Sep 17 00:00:00 2001 From: Michael Trimarchi Date: Fri, 19 Jun 2009 14:50:02 +0200 Subject: [PATCH] i2c: Fix stuck transaction on cpm-i2c driver When a process tries to read/write a disconnected i2c device, it receives a signal (e.g. ctrl-c) and the kernel gets stuck. BUG: soft lockup - CPU#0 stuck for 61s! [I2CEEpromTest:392] NIP: c01628f8 LR: c01628f0 CTR: c00177cc REGS: c39abd70 TRAP: 0901 Not tainted (2.6.25.7-alcore) MSR: 00009032 CR: 42042048 XER: 20000000 TASK = c3889bd0[392] 'I2CEEpromTest' THREAD: c39aa000 GPR00: 00009000 c39abe20 c3889bd0 c39075c8 c39abe28 00000001 00000000 00000001 GPR08: c3889bd0 c39075c8 00009032 c39abe34 00002437 NIP [c01628f8] cpm_i2c_xfer+0x5fc/0x6d0 LR [c01628f0] cpm_i2c_xfer+0x5f4/0x6d0 Call Trace: [c39abe20] [c0162924] cpm_i2c_xfer+0x628/0x6d0 (unreliable) [c39abe90] [c015f6a0] i2c_transfer+0x88/0xb4 [c39abeb0] [c0160164] i2c_master_recv+0x48/0x6c [c39abed0] [c01618dc] i2cdev_read+0x50/0xe4 [c39abef0] [c0068b24] vfs_read+0xc4/0x108 [c39abf10] [c0068f4c] sys_read+0x4c/0x90 [c39abf40] [c000d348] ret_from_syscall+0x0/0x38 Instruction dump: 3bc00064 92610010 3bf201c8 92810014 3b61 This happen because though the wait_event_interruptible_timeout takes the signals into account, the driver does not handle them. We propose to change the wait_event_interruptible_timeout with wait_event_timeout, leaving the signals to be handled in other points on the upper layers. Signed-off-by: Bruno Morelli Signed-off-by: Michael Trimarchi Acked-by: Jochen Friedrich [ben-linux@fluff.org: fix title for patch] Signed-off-by: Ben Dooks --- drivers/i2c/busses/i2c-cpm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index b5db8b883615..9c2e10082b79 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -140,7 +140,7 @@ static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id) dev_dbg(&adap->dev, "Interrupt: %x\n", i); - wake_up_interruptible(&cpm->i2c_wait); + wake_up(&cpm->i2c_wait); return i ? IRQ_HANDLED : IRQ_NONE; } @@ -364,12 +364,12 @@ static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) dev_dbg(&adap->dev, "test ready.\n"); pmsg = &msgs[tptr]; if (pmsg->flags & I2C_M_RD) - ret = wait_event_interruptible_timeout(cpm->i2c_wait, + ret = wait_event_timeout(cpm->i2c_wait, (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) || !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY), 1 * HZ); else - ret = wait_event_interruptible_timeout(cpm->i2c_wait, + ret = wait_event_timeout(cpm->i2c_wait, !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY), 1 * HZ); if (ret == 0) { -- 2.20.1