From: Sergei Shtylyov Date: Sun, 31 Mar 2013 09:54:20 +0000 (+0000) Subject: sh_eth: workaround for spurious ECI interrupt X-Git-Tag: v3.9-rc6~38^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3893b27345ac0ff13c1b9ec20ad50966b810997e;p=pandora-kernel.git sh_eth: workaround for spurious ECI interrupt At least on Renesas R8A7778, EESR.ECI interrupt seems to fire regardless of its mask in EESIPR register. I can 100% reproduce it with the following scenario: target is booted with 'ip=on' option, and so IP-Config opens SoC Ether device but doesn't get a proper reply and then succeeds with on-board SMC chip; then I login and try to bring up the SoC Ether device with 'ifconfig', and I get an ECI interrupt once request_irq() is called by sh_eth_open() (while interrupt mask in EESIPR register is all 0), if that interrupt is accompanied by a pending EESR.FRC (frame receive completion) interrupt, I get kernel oops in sh_eth_rx() because sh_eth_ring_init() hasn't been called yet! The solution I worked out is the following: in sh_eth_interrupt(), mask the interrupt status from EESR register with the interrupt mask from EESIPR register in order not to handle the disabled interrupts -- but forcing EESIPR.M_ECI bit in this mask set because we always need to fully handle EESR.ECI interrupt in sh_eth_error() in order to quench it (as it doesn't get cleared by just writing 1 to the this bit as all the other interrupts). While at it, remove unneeded initializer for 'intr_status' variable and give it *unsigned long* type, matching the type of sh_eth_read()'s result; fix comment. Signed-off-by: Sergei Shtylyov Reviewed-by: Max Filippov Signed-off-by: David S. Miller --- Reading git-diff-tree failed