This series fixes set of isssues observed when CPSW driver module is unloaded/loaded:
1) rmmod: deadlock in cpdma_ctlr_destroy
2) rmmod: L3 back-trace and crash if all net interfaces are down, because CPSW
can be powerred down by PM runtime in this case.
3) insmod: mdio device is not recreated on next insmod
- need to use of_platform_depopulate() in cpsw_remove().
4) rmmod: system crash on omap_device removal
Tested on: am437x-idk, am57xx-beagle-x15
Changes in v2:
- build warning fixed
- added fix for correct omap_device removal
Link on v1:
https://lkml.org/lkml/2016/7/22/240
Grygorii Strashko (4):
net: ethernet: ti: cpdma: fix lockup in cpdma_ctlr_destroy()
drivers: net: cpsw: fix wrong regs access in cpsw_remove
drivers: net: cpsw: use of_platform_depopulate()
ARM: OMAP2+: omap_device: fix crash on omap_device removal
arch/arm/mach-omap2/omap_device.c | 2 +-
drivers/net/ethernet/ti/cpsw.c | 19 +++++++++----------
drivers/net/ethernet/ti/davinci_cpdma.c | 3 ---
3 files changed, 10 insertions(+), 14 deletions(-)
--
2.9.2
Use of_platform_depopulate() in cpsw_remove() instead of
of_device_unregister(), because CSPW child devices will not be
recreated otherwise on next insmod. of_platform_depopulate() is
correct way now as it will ensure that all steps done in
of_platform_populate() are reverted, including cleaning up of
OF_POPULATED flag.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
drivers/net/ethernet/ti/cpsw.c | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
The L3 error will be generated and system will crash during unloading
of CPSW driver if CPSW is used as module and ethX devices are down.
This happens because CPSW can be power off by PM runtime now when ethX
devices are down.
Hence, ensure that CPSW powered up by PM runtime before performing any
deinitialization actions which require CPSW registers access. In case
of PM runtime error just leave cpsw_remove() as we can't do anything
anymore.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
drivers/net/ethernet/ti/cpsw.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
Fix deadlock in cpdma_ctlr_destroy() which is triggered now on
cpsw module removal:
cpsw_remove()
- cpdma_ctlr_destroy()
- spin_lock_irqsave(&ctlr->lock, flags)
- cpdma_ctlr_stop()
- spin_lock_irqsave(&ctlr->lock, flags);
- cpdma_chan_destroy()
- spin_lock_irqsave(&ctlr->lock, flags);
The issue has not been observed before because CPDMA channels have
been destroyed manually by CPSW until commit d941ebe88a41 ("net:
ethernet: ti: cpsw: use destroy ctlr to destroy channels") was merged.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
drivers/net/ethernet/ti/davinci_cpdma.c | 3 ---
1 file changed, 3 deletions(-)
From: Mugunthan V N <hidden> Date: 2016-07-29 08:16:46
On Thursday 28 July 2016 11:20 PM, Grygorii Strashko wrote:
Fix deadlock in cpdma_ctlr_destroy() which is triggered now on
cpsw module removal:
cpsw_remove()
- cpdma_ctlr_destroy()
- spin_lock_irqsave(&ctlr->lock, flags)
- cpdma_ctlr_stop()
- spin_lock_irqsave(&ctlr->lock, flags);
- cpdma_chan_destroy()
- spin_lock_irqsave(&ctlr->lock, flags);
The issue has not been observed before because CPDMA channels have
been destroyed manually by CPSW until commit d941ebe88a41 ("net:
ethernet: ti: cpsw: use destroy ctlr to destroy channels") was merged.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Mugunthan V N <redacted>
Regards
Mugunthan V N
From: Mugunthan V N <hidden> Date: 2016-07-29 08:32:10
On Thursday 28 July 2016 11:20 PM, Grygorii Strashko wrote:
The L3 error will be generated and system will crash during unloading
of CPSW driver if CPSW is used as module and ethX devices are down.
This happens because CPSW can be power off by PM runtime now when ethX
devices are down.
Hence, ensure that CPSW powered up by PM runtime before performing any
deinitialization actions which require CPSW registers access. In case
of PM runtime error just leave cpsw_remove() as we can't do anything
anymore.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Mugunthan V N <redacted>
Regards
Mugunthan V N
From: Mugunthan V N <hidden> Date: 2016-07-29 08:36:37
On Thursday 28 July 2016 11:20 PM, Grygorii Strashko wrote:
Use of_platform_depopulate() in cpsw_remove() instead of
of_device_unregister(), because CSPW child devices will not be
recreated otherwise on next insmod. of_platform_depopulate() is
correct way now as it will ensure that all steps done in
of_platform_populate() are reverted, including cleaning up of
OF_POPULATED flag.
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Mugunthan V N <redacted>
Regards
Mugunthan V N
Below call chain causes system crash when OMAP device is
removed by calling of_platform_depopulate()/device_del():
Should you swap 3 <-> 4 in the series?
Currently patch 3 will introduce the crash you are fixing in patch 4...
No. The key function here is device_del() - of_device_unregister(),
which was used previously has the same issue:
of_device_unregister() -> device_unregister() ->device_del()
In general all these patches are independent and they were created just
in bugs detection order.
quoted
device_del()
- blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
BUS_NOTIFY_DEL_DEVICE, dev);
- _omap_device_notifier_call()
- omap_device_delete()
- od->pdev->archdata.od = NULL;
kfree(od->hwmods);
kfree(od);
- bus_remove_device()
- device_release_driver()
- __device_release_driver()
- pm_runtime_get_sync()
- _od_runtime_resume()
- omap_hwmod_enable() <- OOPS od's delted already
Backtrace:
Unable to handle kernel NULL pointer dereference at virtual address 0000000d
pgd = eb100000
[0000000d] *pgd=ad6e1831, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#1] PREEMPT SMP ARM
CPU: 1 PID: 1273 Comm: modprobe Not tainted 4.4.15-rt19-00115-ge4d3cd3-dirty #68
Hardware name: Generic DRA74X (Flattened Device Tree)
task: eb1ee800 ti: ec962000 task.ti: ec962000
PC is at omap_device_enable+0x10/0x90
LR is at _od_runtime_resume+0x10/0x24
[...]
[<c00299dc>] (omap_device_enable) from [<c0029a6c>] (_od_runtime_resume+0x10/0x24)
[<c0029a6c>] (_od_runtime_resume) from [<c04ad404>] (__rpm_callback+0x20/0x34)
[<c04ad404>] (__rpm_callback) from [<c04ad438>] (rpm_callback+0x20/0x80)
[<c04ad438>] (rpm_callback) from [<c04aee28>] (rpm_resume+0x48c/0x964)
[<c04aee28>] (rpm_resume) from [<c04af360>] (__pm_runtime_resume+0x60/0x88)
[<c04af360>] (__pm_runtime_resume) from [<c04a4974>] (__device_release_driver+0x30/0x100)
[<c04a4974>] (__device_release_driver) from [<c04a4a60>] (device_release_driver+0x1c/0x28)
[<c04a4a60>] (device_release_driver) from [<c04a38c0>] (bus_remove_device+0xec/0x144)
[<c04a38c0>] (bus_remove_device) from [<c04a0764>] (device_del+0x10c/0x210)
[<c04a0764>] (device_del) from [<c04a67b0>] (platform_device_del+0x18/0x84)
[<c04a67b0>] (platform_device_del) from [<c04a6828>] (platform_device_unregister+0xc/0x20)
[<c04a6828>] (platform_device_unregister) from [<c05adcfc>] (of_platform_device_destroy+0x8c/0x90)
[<c05adcfc>] (of_platform_device_destroy) from [<c04a02f0>] (device_for_each_child+0x4c/0x78)
[<c04a02f0>] (device_for_each_child) from [<c05adc5c>] (of_platform_depopulate+0x30/0x44)
[<c05adc5c>] (of_platform_depopulate) from [<bf123920>] (cpsw_remove+0x68/0xf4 [ti_cpsw])
[<bf123920>] (cpsw_remove [ti_cpsw]) from [<c04a68d8>] (platform_drv_remove+0x24/0x3c)
[<c04a68d8>] (platform_drv_remove) from [<c04a49c8>] (__device_release_driver+0x84/0x100)
[<c04a49c8>] (__device_release_driver) from [<c04a4b20>] (driver_detach+0xac/0xb0)
[<c04a4b20>] (driver_detach) from [<c04a3be8>] (bus_remove_driver+0x60/0xd4)
[<c04a3be8>] (bus_remove_driver) from [<c00d9870>] (SyS_delete_module+0x184/0x20c)
[<c00d9870>] (SyS_delete_module) from [<c0010540>] (ret_fast_syscall+0x0/0x1c)
Code: e3500000 e92d4070 1590630c 01a06000 (e5d6300d)
Hence, fix it by using BUS_NOTIFY_REMOVED_DEVICE event for OMAP device
deletion which is sent when DD has finished processing of device
deletion.
Cc: Tony Lindgren <tony@atomide.com>
Cc: Tero Kristo <redacted>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
arch/arm/mach-omap2/omap_device.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
This series fixes set of isssues observed when CPSW driver module is unloaded/loaded:
1) rmmod: deadlock in cpdma_ctlr_destroy
2) rmmod: L3 back-trace and crash if all net interfaces are down, because CPSW
can be powerred down by PM runtime in this case.
3) insmod: mdio device is not recreated on next insmod
- need to use of_platform_depopulate() in cpsw_remove().
4) rmmod: system crash on omap_device removal
Tested on: am437x-idk, am57xx-beagle-x15
Changes in v2:
- build warning fixed
- added fix for correct omap_device removal
Link on v1:
https://lkml.org/lkml/2016/7/22/240