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authorMaxime Bizon <mbizon@freebox.fr>2007-01-05 17:54:05 +0100
committerJean Delvare <khali@arrakis.delvare>2007-01-05 17:54:05 +0100
commit3269bb63eb076318ce4fb554851d047e1c9aa1a5 (patch)
treed589a0710833f7bb16d64db5a2b3d314b62761ee
parentb119dc3f992183a04e508fc0a09f550eb19bf30e (diff)
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i2c-mv64xxx: Fix random oops at boot
I have a Marvell board which has the same i2c hw block than mv64xxx, so I'm trying to use i2c-mv64xxx driver. But I get the following random oops at boot: Unable to handle kernel NULL pointer dereference at virtual address 00000002 Backtrace: [<c0397e4c>] (mv64xxx_i2c_intr+0x0/0x2b8) from [<c02879c4>] (__do_irq+0x4c/0x8c) [<c0287978>] (__do_irq+0x0/0x8c) from [<c0287c0c>] (do_level_IRQ+0x68/0xc0) r8 = C0501E08 r7 = 00000005 r6 = C0501E08 r5 = 00000005 r4 = C048BB78 [<c0287ba4>] (do_level_IRQ+0x0/0xc0) from [<c02885f8>] (asm_do_IRQ+0x50/0x134) r6 = C0449C78 r5 = F1020000 r4 = FFFFFFFF [<c02885a8>] (asm_do_IRQ+0x0/0x134) from [<c02869c4>] (__irq_svc+0x24/0x100) r8 = C1CAC400 r7 = 00000005 r6 = 00000002 r5 = F1020000 r4 = FFFFFFFF [<c0287efc>] (setup_irq+0x0/0x124) from [<c02880d0>] (request_irq+0xb0/0xd0) r7 = C041B2AC r6 = C0397E4C r5 = 00000000 r4 = 00000005 [<c0288020>] (request_irq+0x0/0xd0) from [<c03985f4>] (mv64xxx_i2c_probe+0x148/0x244) [<c03984ac>] (mv64xxx_i2c_probe+0x0/0x244) from [<c038bedc>] (platform_drv_probe+0x20/0x24) The oops is caused by a spurious interrupt that occurs when request_irq is called. mv64xxx_i2c_fsm() tries to read drv_data->msg, which is NULL. I noticed that hardware init is done after requesting irq. Thus any pending irq from previous hardware usage may cause this. The following patch fixes it: Signed-off-by: Maxime Bizon <mbizon@freebox.fr> Acked-by: Mark A. Greer <mgreer@mvista.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
-rw-r--r--drivers/i2c/busses/i2c-mv64xxx.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index bbc8e3a..4901736 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -529,6 +529,8 @@ mv64xxx_i2c_probe(struct platform_device *pd)
platform_set_drvdata(pd, drv_data);
i2c_set_adapdata(&drv_data->adapter, drv_data);
+ mv64xxx_i2c_hw_init(drv_data);
+
if (request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
MV64XXX_I2C_CTLR_NAME, drv_data)) {
dev_err(&drv_data->adapter.dev,
@@ -542,8 +544,6 @@ mv64xxx_i2c_probe(struct platform_device *pd)
goto exit_free_irq;
}
- mv64xxx_i2c_hw_init(drv_data);
-
return 0;
exit_free_irq: