|
enic_dev_wait() has a BUG_ON(in_interrupt()).
Chasing the callers of enic_dev_wait() revealed the gems of enic_reset()
and enic_tx_hang_reset() which are both invoked through work queues in
order to be able to call rtnl_lock(). So far so good.
After locking rtnl both functions acquire enic::enic_api_lock which
serializes against the (ab)use from infiniband. This is where the
trainwreck starts.
enic::enic_api_lock is a spin_lock() which implicitly disables preemption,
but both functions invoke a ton of functions under that lock which can
sleep. The BUG_ON(in_interrupt()) does not trigger in that case because it
can't detect the preempt disabled condition.
This clearly has never been tested with any of the mandatory debug options
for 7+ years, which would have caught that for sure.
Cure it by adding a enic_api_busy member to struct enic, which is modified
and evaluated with enic::enic_api_lock held.
If enic_api_devcmd_proxy_by_index() observes enic::enic_api_busy as true,
it drops enic::enic_api_lock and busy waits for enic::enic_api_busy to
become false.
It would be smarter to wait for a completion of that busy period, but
enic_api_devcmd_proxy_by_index() is called with other spin locks held which
obviously can't sleep.
Remove the BUG_ON(in_interrupt()) check as well because it's incomplete and
with proper debugging enabled the problem would have been caught from the
debug checks in schedule_timeout().
Fixes: 0b038566c0ea ("drivers/net: enic: Add an interface for USNIC to interact with firmware")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
As part of the W=1 cleanups for ethernet, a million [*] driver
comments had to be cleaned up to get the W=1 compilation to
succeed. This change finally makes the drivers/net/ethernet tree
compile with W=1 set on the command line. NOTE: The kernel uses
kdoc style (see Documentation/process/kernel-doc.rst) when
documenting code, not doxygen or other styles.
After this patch the x86_64 build has no warnings from W=1, however
scripts/kernel-doc says there are 1545 more warnings in source files, that
I need to develop a script to fix in a followup patch.
The errors fixed here are all kdoc of a few classes, with a few outliers:
In file included from drivers/net/ethernet/qlogic/netxen/netxen_nic_hw.c:10:
drivers/net/ethernet/qlogic/netxen/netxen_nic.h:1193:18: warning: ‘FW_DUMP_LEVELS’ defined but not used [-Wunused-const-variable=]
1193 | static const u32 FW_DUMP_LEVELS[] = { 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff };
| ^~~~~~~~~~~~~~
... repeats 4 times...
drivers/net/ethernet/sun/cassini.c:2084:24: warning: suggest braces around empty body in an ‘else’ statement [-Wempty-body]
2084 | RX_USED_ADD(page, i);
drivers/net/ethernet/natsemi/ns83820.c: In function ‘phy_intr’:
drivers/net/ethernet/natsemi/ns83820.c:603:6: warning: variable ‘tbisr’ set but not used [-Wunused-but-set-variable]
603 | u32 tbisr, tanar, tanlpar;
| ^~~~~
drivers/net/ethernet/natsemi/ns83820.c: In function ‘ns83820_get_link_ksettings’:
drivers/net/ethernet/natsemi/ns83820.c:1207:11: warning: variable ‘tanar’ set but not used [-Wunused-but-set-variable]
1207 | u32 cfg, tanar, tbicr;
| ^~~~~
drivers/net/ethernet/packetengines/yellowfin.c:1063:18: warning: variable ‘yf_size’ set but not used [-Wunused-but-set-variable]
1063 | int data_size, yf_size;
| ^~~~~~~
Normal kdoc fixes:
warning: Function parameter or member 'x' not described in 'y'
warning: Excess function parameter 'x' description in 'y'
warning: Cannot understand <string> on line <NNN> - I thought it was a doc line
[*] - ok it wasn't quite a million, but it felt like it.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
