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authorStefano Babic <sbabic@denx.de>2012-10-15 11:20:22 +0200
committerFelipe Balbi <balbi@ti.com>2012-10-15 15:20:27 +0300
commit6ff1f3d3bd7c69c62ca5773b1b684bce42eff06a (patch)
tree462d8c91e1a359c10f8134190bda9ac7e25c11ff /drivers/usb/musb/am35x.c
parent041d81f493d90c940ec41f0ec98bc7c4f2fba431 (diff)
usb: musb: am35xx: drop spurious unplugging a device
On AM3517, tx and rx interrupt are detected together with the disconnect event. This generates a kernel panic in musb_interrupt, because rx / tx are handled after disconnect. This issue was seen on a Technexion's TAM3517 SOM. Unplugging a device, tx / rx interrupts together with disconnect are detected. This brings to kernel panic like this: [ 68.526153] Unable to handle kernel NULL pointer dereference at virtual address 00000011 [ 68.534698] pgd = c0004000 [ 68.537536] [00000011] *pgd=00000000 [ 68.541351] Internal error: Oops: 17 [#1] ARM [ 68.545928] Modules linked in: [ 68.549163] CPU: 0 Not tainted (3.6.0-rc5-00020-g9e05905 #178) [ 68.555694] PC is at rxstate+0x8/0xdc [ 68.559539] LR is at musb_interrupt+0x98/0x858 [ 68.564239] pc : [<c035cd88>] lr : [<c035af1c>] psr: 40000193 [ 68.564239] sp : ce83fb40 ip : d0906410 fp : 00000000 [ 68.576293] r10: 00000000 r9 : cf3b0e40 r8 : 00000002 [ 68.581817] r7 : 00000019 r6 : 00000001 r5 : 00000001 r4 : 000000d4 [ 68.588684] r3 : 00000000 r2 : 00000000 r1 : ffffffcc r0 : cf23c108 [ 68.595550] Flags: nZcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment ke Note: this behavior is not seen with a USB hub, while it is easy to reproduce connecting a USB-pen directly to the USB-A of the board. Drop tx / rx interrupts if disconnect is detected. Signed-off-by: Stefano Babic <sbabic@denx.de> CC: Felipe Balbi <balbi@ti.com> Cc: stable@vger.kernel.org # 3.5 3.6 Tested-by: Dmitry Lifshitz <lifshitz@compulab.co.il> Tested-by: Igor Grinberg <grinberg@compulab.co.il> Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers/usb/musb/am35x.c')
-rw-r--r--drivers/usb/musb/am35x.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/usb/musb/am35x.c b/drivers/usb/musb/am35x.c
index 457f25e62c51..c964d6af178b 100644
--- a/drivers/usb/musb/am35x.c
+++ b/drivers/usb/musb/am35x.c
@@ -305,6 +305,12 @@ static irqreturn_t am35x_musb_interrupt(int irq, void *hci)
ret = IRQ_HANDLED;
}
+ /* Drop spurious RX and TX if device is disconnected */
+ if (musb->int_usb & MUSB_INTR_DISCONNECT) {
+ musb->int_tx = 0;
+ musb->int_rx = 0;
+ }
+
if (musb->int_tx || musb->int_rx || musb->int_usb)
ret |= musb_interrupt(musb);