| Message ID | 1289570109-8160-2-git-send-email-Joakim.Tjernlund@transmode.se (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Fri, Nov 12, 2010 at 02:55:09PM +0100, Joakim Tjernlund wrote: > This script: > while [ 1==1 ] ; do ifconfig eth0 up; usleep 1950000 ;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 <Joakim.Tjernlund@transmode.se> It's unclear where exactly adjust_link() hangs, but the patch looks as the right thing overall. Thanks! Reviewed-by: Anton Vorontsov <cbouatmailru@gmail.com> > --- > 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, 0x00000000);
From: Anton Vorontsov <cbouatmailru@gmail.com> 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 1950000 ;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 <Joakim.Tjernlund@transmode.se> > > It's unclear where exactly adjust_link() hangs, but the patch > looks as the right thing overall. > > Thanks! > > Reviewed-by: Anton Vorontsov <cbouatmailru@gmail.com> Applied.
Anton Vorontsov <cbouatmailru@gmail.com> 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 1950000 ;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 <Joakim.Tjernlund@transmode.se> > > 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
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, 0x00000000);
This script: while [ 1==1 ] ; do ifconfig eth0 up; usleep 1950000 ;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 0 572 369 0x00000000 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 <Joakim.Tjernlund@transmode.se> --- drivers/net/ucc_geth.c | 10 +++++++--- 1 files changed, 7 insertions(+), 3 deletions(-)