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| author | Jonas Gorski <jogo@openwrt.org> | 2015-06-17 09:55:13 +0000 |
|---|---|---|
| committer | Jonas Gorski <jogo@openwrt.org> | 2015-06-17 09:55:13 +0000 |
| commit | 01796e87b169ef53d51f88a32d2550c1f914808a (patch) | |
| tree | ba820f79412251ab7d0c95976989cb4ec0ed1fa0 /target/linux | |
| parent | 9a59b350b7587eae4bcf6091b4dc86a4ee92bcf6 (diff) | |
| download | upstream-01796e87b169ef53d51f88a32d2550c1f914808a.tar.gz upstream-01796e87b169ef53d51f88a32d2550c1f914808a.tar.bz2 upstream-01796e87b169ef53d51f88a32d2550c1f914808a.zip | |
ar71xx: rb493g: fix gpio-mdio accesses under load
It seems that there are maximum timings for mdio accesses that can be
hit when the system is under load and the thread is scheduled during
a read or write access. Since there is no way of knowing if this
happens as there is not even a parity bit, try to work around it
by disabling interrupts during any gpio-mdio accesses.
Performance impact seems to be neglectable, as mdio accesses are not
that often.
Hopefully fixes #19500.
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
SVN-Revision: 46012
Diffstat (limited to 'target/linux')
| -rw-r--r-- | target/linux/ar71xx/patches-3.18/904-phy-mdio-bitbang-prevent-rescheduling-during-command.patch | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/target/linux/ar71xx/patches-3.18/904-phy-mdio-bitbang-prevent-rescheduling-during-command.patch b/target/linux/ar71xx/patches-3.18/904-phy-mdio-bitbang-prevent-rescheduling-during-command.patch new file mode 100644 index 0000000000..68f86e0e09 --- /dev/null +++ b/target/linux/ar71xx/patches-3.18/904-phy-mdio-bitbang-prevent-rescheduling-during-command.patch @@ -0,0 +1,61 @@ +From 66e584435ac0de6e0abeb6d7166fe4fe25d6bb73 Mon Sep 17 00:00:00 2001 +From: Jonas Gorski <jogo@openwrt.org> +Date: Tue, 16 Jun 2015 13:15:08 +0200 +Subject: [PATCH] phy/mdio-bitbang: prevent rescheduling during command + +It seems some phys have some maximum timings for accessing the MDIO line, +resulting in bit errors under cpu stress. Prevent this from happening by +disabling interrupts when sending commands. + +Signed-off-by: Jonas Gorski <jogo@openwrt.org> +--- + drivers/net/phy/mdio-bitbang.c | 9 +++++++++ + 1 file changed, 9 insertions(+) + +--- a/drivers/net/phy/mdio-bitbang.c ++++ b/drivers/net/phy/mdio-bitbang.c +@@ -17,6 +17,7 @@ + * kind, whether express or implied. + */ + ++#include <linux/irqflags.h> + #include <linux/module.h> + #include <linux/mdio-bitbang.h> + #include <linux/types.h> +@@ -156,7 +157,9 @@ static int mdiobb_read(struct mii_bus *b + { + struct mdiobb_ctrl *ctrl = bus->priv; + int ret, i; ++ long flags; + ++ local_irq_save(flags); + if (reg & MII_ADDR_C45) { + reg = mdiobb_cmd_addr(ctrl, phy, reg); + mdiobb_cmd(ctrl, MDIO_C45_READ, phy, reg); +@@ -169,13 +172,17 @@ static int mdiobb_read(struct mii_bus *b + + ret = mdiobb_get_num(ctrl, 16); + mdiobb_get_bit(ctrl); ++ local_irq_restore(flags); ++ + return ret; + } + + static int mdiobb_write(struct mii_bus *bus, int phy, int reg, u16 val) + { + struct mdiobb_ctrl *ctrl = bus->priv; ++ long flags; + ++ local_irq_save(flags); + if (reg & MII_ADDR_C45) { + reg = mdiobb_cmd_addr(ctrl, phy, reg); + mdiobb_cmd(ctrl, MDIO_C45_WRITE, phy, reg); +@@ -190,6 +197,8 @@ static int mdiobb_write(struct mii_bus * + + ctrl->ops->set_mdio_dir(ctrl, 0); + mdiobb_get_bit(ctrl); ++ local_irq_restore(flags); ++ + return 0; + } + |