Commit aac27c7a authored by Russell King's avatar Russell King Committed by David S. Miller

net: fec: use reinit_completion() in mdio accessor functions

Rather than re-initialising the entire completion on every mdio access,
use reinit_completion() which only resets the completion count.  This
avoids possible reinitialisation of the contained spinlock and waitqueue
while they may be in use (eg, mid-completion.)

Such an event could occur if there's a long delay in interrupt handling
causing the mdio accessor to time out, then a second access comes in
while the interrupt handler on a different CPU has called complete().
Another scenario where this has been observed is while locking has
been missing at the phy layer, allowing concurrent attempts to access
the MDIO bus.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 05a7f582
...@@ -1778,7 +1778,7 @@ static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum) ...@@ -1778,7 +1778,7 @@ static int fec_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
return ret; return ret;
fep->mii_timeout = 0; fep->mii_timeout = 0;
init_completion(&fep->mdio_done); reinit_completion(&fep->mdio_done);
/* start a read op */ /* start a read op */
writel(FEC_MMFR_ST | FEC_MMFR_OP_READ | writel(FEC_MMFR_ST | FEC_MMFR_OP_READ |
...@@ -1817,7 +1817,7 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum, ...@@ -1817,7 +1817,7 @@ static int fec_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
return ret; return ret;
fep->mii_timeout = 0; fep->mii_timeout = 0;
init_completion(&fep->mdio_done); reinit_completion(&fep->mdio_done);
/* start a write op */ /* start a write op */
writel(FEC_MMFR_ST | FEC_MMFR_OP_WRITE | writel(FEC_MMFR_ST | FEC_MMFR_OP_WRITE |
......
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