Currently we're getting IRQs after lots of resources are already
allocated:
* netdev
* clocks
* MDIO bus
Also HW gets initialized by the time when checking IRQs as well.
Now there's a possibility for master interrupt controller to be not
probed yet. This will lead to exit from GMAC probe routine with "-
EPROBE_DEFER" and so deferred probe will hapen later on.
But since we exited the first GMAC probe without release of all
allocated resources there could be conflicts on subsequent probes.
For example this is what happens for me:
--->8---
stmmaceth e0018000.ethernet: no reset control found
stmmac - user ID: 0x10, Synopsys ID: 0x37
Ring mode enabled
DMA HW capability register supported
Normal descriptors
RX Checksum Offload Engine supported (type 2)
TX Checksum insertion supported
Enable RX Mitigation via HW Watchdog Timer
libphy: stmmac: probed
eth0: PHY ID 20005c7a at 1 IRQ POLL (stmmac-0:01) active
platform e0018000.ethernet: Driver stmmaceth requests probe deferral
...
...
...
stmmaceth e0018000.ethernet: no reset control found
stmmac - user ID: 0x10, Synopsys ID: 0x37
Ring mode enabled
DMA HW capability register supported
Normal descriptors
RX Checksum Offload Engine supported (type 2)
TX Checksum insertion supported
Enable RX Mitigation via HW Watchdog Timer
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x4e/0x68()
sysfs: cannot create duplicate filename
'/devices/platform/axs10x_mb/e0018000.ethernet/mdio_bus/stmmac-0'
CPU: 0 PID: 6 Comm: kworker/u2:0 Not tainted 4.0.0-rc1-next-20150303+#8
Workqueue: deferwq deferred_probe_work_func
Stack Trace:
arc_unwind_core+0xb8/0x114
warn_slowpath_common+0x5a/0x8c
warn_slowpath_fmt+0x2e/0x38
sysfs_warn_dup+0x4e/0x68
sysfs_create_dir_ns+0x98/0xa0
kobject_add_internal+0x8c/0x2e8
kobject_add+0x4a/0x8c
device_add+0xc6/0x448
mdiobus_register+0x6c/0x164
stmmac_mdio_register+0x112/0x264
stmmac_dvr_probe+0x6c0/0x85c
stmmac_pltfr_probe+0x2e4/0x50c
platform_drv_probe+0x26/0x5c
really_probe+0x76/0x1dc
bus_for_each_drv+0x42/0x7c
device_attach+0x64/0x6c
bus_probe_device+0x74/0xa4
deferred_probe_work_func+0x50/0x84
process_one_work+0xf8/0x2cc
worker_thread+0x110/0x478
kthread+0x8a/0x9c
ret_from_fork+0x14/0x18
---[ end trace a2dfaa7d630c8be1 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6 at lib/kobject.c:240
kobject_add_internal+0x218/0x2e8()
kobject_add_internal failed for stmmac-0 with -EEXIST, don't try to
register things with the same name in the same di.
CPU: 0 PID: 6 Comm: kworker/u2:0 Tainted: G W
4.0.0-rc1-next-20150303+ #8
Workqueue: deferwq deferred_probe_work_func
Stack Trace:
arc_unwind_core+0xb8/0x114
warn_slowpath_common+0x5a/0x8c
warn_slowpath_fmt+0x2e/0x38
kobject_add_internal+0x218/0x2e8
kobject_add+0x4a/0x8c
device_add+0xc6/0x448
mdiobus_register+0x6c/0x164
stmmac_mdio_register+0x112/0x264
stmmac_dvr_probe+0x6c0/0x85c
stmmac_pltfr_probe+0x2e4/0x50c
platform_drv_probe+0x26/0x5c
really_probe+0x76/0x1dc
bus_for_each_drv+0x42/0x7c
device_attach+0x64/0x6c
bus_probe_device+0x74/0xa4
deferred_probe_work_func+0x50/0x84
process_one_work+0xf8/0x2cc
worker_thread+0x110/0x478
kthread+0x8a/0x9c
ret_from_fork+0x14/0x18
---[ end trace a2dfaa7d630c8be2 ]---
libphy: mii_bus stmmac-0 failed to register
: Cannot register as MDIO bus
stmmac_pltfr_probe: main driver probe failed
stmmaceth: probe of e0018000.ethernet failed with error -22
--->8---
Essential fix is to check for IRQs availability as early as possible and
then safely go to deferred probe if IRQs are not there yet.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Sonic Zhang <sonic.zhang@analog.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
8f02d8da96