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https://gitee.com/bianbu-linux/linux-6.6
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796a2665ca
On arm imx6, when opening the chip's netdev, the whole Linux
kernel intermittently hangs/freezes.
This is caused by a bug in the driver code which tests if pcie
interrupts are working correctly, using the software interrupt:
1. open: enable the software interrupt
2. open: tell the chip to assert the software interrupt
3. open: wait for flag
4. ISR: acknowledge s/w interrupt, set flag
5. open: notice flag, disable the s/w interrupt, continue
Unfortunately the ISR only acknowledges the s/w interrupt, but
does not disable it. This will re-trigger the ISR in a tight
loop.
On some (lucky) platforms, open proceeds to disable the s/w
interrupt even while the ISR is 'spinning'. On arm imx6,
the spinning ISR does not allow open to proceed, resulting
in a hung Linux kernel.
Fix minimally by disabling the s/w interrupt in the ISR, which
will prevent it from spinning. This won't break anything because
the s/w interrupt is used as a one-shot interrupt.
Note that this is a minimal fix, overlooking many possible
cleanups, e.g.:
- lan743x_intr_software_isr() is completely redundant and reads
INT_STS twice for no apparent reason
- disabling the s/w interrupt in lan743x_intr_test_isr() is now
redundant, but harmless
- waiting on software_isr_flag can be converted from a sleeping
poll loop to wait_event_timeout()
Fixes:
|
||
|---|---|---|
| .. | ||
| enc28j60.c | ||
| enc28j60_hw.h | ||
| encx24j600-regmap.c | ||
| encx24j600.c | ||
| encx24j600_hw.h | ||
| Kconfig | ||
| lan743x_ethtool.c | ||
| lan743x_ethtool.h | ||
| lan743x_main.c | ||
| lan743x_main.h | ||
| lan743x_ptp.c | ||
| lan743x_ptp.h | ||
| Makefile | ||