AcoSail/kernel_optimize_test
8
0
Fork 0
forked from luck/tmp_suning_uos_patched
Code Pull Requests Activity

usb: musb: am35xx: drop spurious unplugging a device

Browse Source 
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>
This commit is contained in:
Stefano Babic 2012-10-15 11:20:22 +02:00 committed by Felipe Balbi
parent 041d81f493
commit 6ff1f3d3bd
1 changed files with 6 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
drivers/usb/musb/am35x.c
View File

@ -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);