Re: [PATCH 2/2] ucc_geth: Fix deadlock
Anton Vorontsov wrote on 2010/11/12 15:09:47: > > On Fri, Nov 12, 2010 at 02:55:09PM +0100, Joakim Tjernlund wrote: > > This script: > > while [ 1==1 ] ; do ifconfig eth0 up; usleep 195 ;ifconfig eth0 down; > > dmesg -c ;done > > causes in just a second or two: > > INFO: task ifconfig:572 blocked for more than 120 seconds. > [...] > > The reason appears to be ucc_geth_stop meets adjust_link as the > > PHY reports PHY changes. I belive adjust_link hangs somewhere, > > holding the PHY lock, because ucc_geth_stop disabled the > > controller HW. > > Fix is to stop the PHY before disabling the controller. > > > > Signed-off-by: Joakim Tjernlund > > It's unclear where exactly adjust_link() hangs, but the patch > looks as the right thing overall. Yes, I too cannot find where it is hanging, just that it is hanging somewhere. I am starting to think it is hanging somewhere else. Anyhow, the hang goes away 100% when this patch is applied. Jocke ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 2/2] ucc_geth: Fix deadlock
From: Anton Vorontsov Date: Fri, 12 Nov 2010 17:09:47 +0300 > On Fri, Nov 12, 2010 at 02:55:09PM +0100, Joakim Tjernlund wrote: >> This script: >> while [ 1==1 ] ; do ifconfig eth0 up; usleep 195 ;ifconfig eth0 down; >> dmesg -c ;done >> causes in just a second or two: >> INFO: task ifconfig:572 blocked for more than 120 seconds. > [...] >> The reason appears to be ucc_geth_stop meets adjust_link as the >> PHY reports PHY changes. I belive adjust_link hangs somewhere, >> holding the PHY lock, because ucc_geth_stop disabled the >> controller HW. >> Fix is to stop the PHY before disabling the controller. >> >> Signed-off-by: Joakim Tjernlund > > It's unclear where exactly adjust_link() hangs, but the patch > looks as the right thing overall. > > Thanks! > > Reviewed-by: Anton Vorontsov Applied. ___ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
Re: [PATCH 2/2] ucc_geth: Fix deadlock
On Fri, Nov 12, 2010 at 02:55:09PM +0100, Joakim Tjernlund wrote:
> This script:
> while [ 1==1 ] ; do ifconfig eth0 up; usleep 195 ;ifconfig eth0 down;
> dmesg -c ;done
> causes in just a second or two:
> INFO: task ifconfig:572 blocked for more than 120 seconds.
[...]
> The reason appears to be ucc_geth_stop meets adjust_link as the
> PHY reports PHY changes. I belive adjust_link hangs somewhere,
> holding the PHY lock, because ucc_geth_stop disabled the
> controller HW.
> Fix is to stop the PHY before disabling the controller.
>
> Signed-off-by: Joakim Tjernlund
It's unclear where exactly adjust_link() hangs, but the patch
looks as the right thing overall.
Thanks!
Reviewed-by: Anton Vorontsov
> ---
> drivers/net/ucc_geth.c | 10 +++---
> 1 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c
> index 6c254ed..06a5db3 100644
> --- a/drivers/net/ucc_geth.c
> +++ b/drivers/net/ucc_geth.c
> @@ -2050,12 +2050,16 @@ static void ucc_geth_stop(struct ucc_geth_private
> *ugeth)
>
> ugeth_vdbg("%s: IN", __func__);
>
> + /*
> + * Tell the kernel the link is down.
> + * Must be done before disabling the controller
> + * or deadlock may happen.
> + */
> + phy_stop(phydev);
> +
> /* Disable the controller */
> ugeth_disable(ugeth, COMM_DIR_RX_AND_TX);
>
> - /* Tell the kernel the link is down */
> - phy_stop(phydev);
> -
> /* Mask all interrupts */
> out_be32(ugeth->uccf->p_uccm, 0x);
___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
[PATCH 2/2] ucc_geth: Fix deadlock
This script:
while [ 1==1 ] ; do ifconfig eth0 up; usleep 195 ;ifconfig eth0 down;
dmesg -c ;done
causes in just a second or two:
INFO: task ifconfig:572 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
ifconfig D 0ff65760 0 572369 0x
Call Trace:
[c6157be0] [c6008460] 0xc6008460 (unreliable)
[c6157ca0] [c0008608] __switch_to+0x4c/0x6c
[c6157cb0] [c028fecc] schedule+0x184/0x310
[c6157ce0] [c0290e54] __mutex_lock_slowpath+0xa4/0x150
[c6157d20] [c0290c48] mutex_lock+0x44/0x48
[c6157d30] [c01aba74] phy_stop+0x20/0x70
[c6157d40] [c01aef40] ucc_geth_stop+0x30/0x98
[c6157d60] [c01b18fc] ucc_geth_close+0x9c/0xdc
[c6157d80] [c01db0cc] __dev_close+0xa0/0xd0
[c6157d90] [c01deddc] __dev_change_flags+0x8c/0x148
[c6157db0] [c01def54] dev_change_flags+0x1c/0x64
[c6157dd0] [c0237ac8] devinet_ioctl+0x678/0x784
[c6157e50] [c0239a58] inet_ioctl+0xb0/0xbc
[c6157e60] [c01cafa8] sock_ioctl+0x174/0x2a0
[c6157e80] [c009a16c] vfs_ioctl+0xcc/0xe0
[c6157ea0] [c009a998] do_vfs_ioctl+0xc4/0x79c
[c6157f10] [c009b0b0] sys_ioctl+0x40/0x74
[c6157f40] [c00117c4] ret_from_syscall+0x0/0x38
The reason appears to be ucc_geth_stop meets adjust_link as the
PHY reports PHY changes. I belive adjust_link hangs somewhere,
holding the PHY lock, because ucc_geth_stop disabled the
controller HW.
Fix is to stop the PHY before disabling the controller.
Signed-off-by: Joakim Tjernlund
---
drivers/net/ucc_geth.c | 10 +++---
1 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c
index 6c254ed..06a5db3 100644
--- a/drivers/net/ucc_geth.c
+++ b/drivers/net/ucc_geth.c
@@ -2050,12 +2050,16 @@ static void ucc_geth_stop(struct ucc_geth_private
*ugeth)
ugeth_vdbg("%s: IN", __func__);
+ /*
+* Tell the kernel the link is down.
+* Must be done before disabling the controller
+* or deadlock may happen.
+*/
+ phy_stop(phydev);
+
/* Disable the controller */
ugeth_disable(ugeth, COMM_DIR_RX_AND_TX);
- /* Tell the kernel the link is down */
- phy_stop(phydev);
-
/* Mask all interrupts */
out_be32(ugeth->uccf->p_uccm, 0x);
--
1.7.2.2
___
Linuxppc-dev mailing list
Linuxppc-dev@lists.ozlabs.org
https://lists.ozlabs.org/listinfo/linuxppc-dev
