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| author | Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> | 2013-03-31 13:54:20 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-04-01 03:42:33 +0400 |
| commit | 3893b27345ac0ff13c1b9ec20ad50966b810997e (patch) | |
| tree | 509d25a4cbd3b3d40f82fde35c3b05ebbaeab555 | |
| parent | 1e1b812bbe1069fc8e2e372dca7d5f541c7a8ceb (diff) | |
| download | linux-3893b27345ac0ff13c1b9ec20ad50966b810997e.tar.xz | |
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 <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Max Filippov <max.filippov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/renesas/sh_eth.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index 1ca8b2b10adc..44f7904e5054 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -1324,12 +1324,18 @@ static irqreturn_t sh_eth_interrupt(int irq, void *netdev) struct sh_eth_private *mdp = netdev_priv(ndev); struct sh_eth_cpu_data *cd = mdp->cd; irqreturn_t ret = IRQ_NONE; - u32 intr_status = 0; + unsigned long intr_status; spin_lock(&mdp->lock); - /* Get interrpt stat */ + /* Get interrupt status */ intr_status = sh_eth_read(ndev, EESR); + /* Mask it with the interrupt mask, forcing ECI interrupt to be always + * enabled since it's the one that comes thru regardless of the mask, + * and we need to fully handle it in sh_eth_error() in order to quench + * it as it doesn't get cleared by just writing 1 to the ECI bit... + */ + intr_status &= sh_eth_read(ndev, EESIPR) | DMAC_M_ECI; /* Clear interrupt */ if (intr_status & (EESR_FRC | EESR_RMAF | EESR_RRF | EESR_RTLF | EESR_RTSF | EESR_PRE | EESR_CERF | |