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由 Ben Hutchings 提交于
In order to stop the RX path accessing the RX ring while it's being stopped or resized, we clear the interrupt mask (EESIPR) and then call free_irq() or synchronise_irq(). This is insufficient because the interrupt handler or NAPI poller may set EESIPR again after we clear it. Also, in sh_eth_set_ringparam() we currently don't disable NAPI polling at all. I could easily trigger a crash by running the loop: while ethtool -G eth0 rx 128 && ethtool -G eth0 rx 64; do echo -n .; done and 'ping -f' toward the sh_eth port from another machine. To fix this: - Add a software flag (irq_enabled) to signal whether interrupts should be enabled - In the interrupt handler, if the flag is clear then clear EESIPR and return - In the NAPI poller, if the flag is clear then don't set EESIPR - Set the flag before enabling interrupts in sh_eth_dev_init() and sh_eth_set_ringparam() - Clear the flag and serialise with the interrupt and NAPI handlers before clearing EESIPR in sh_eth_close() and sh_eth_set_ringparam() After this, I could run the loop for 100,000 iterations successfully. Signed-off-by: NBen Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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