target/linux/ar71xx/patches-4.4/901-phy-mdio-bitbang-prevent-rescheduling-during-command.patch

   1 From 66e584435ac0de6e0abeb6d7166fe4fe25d6bb73 Mon Sep 17 00:00:00 2001
   2 From: Jonas Gorski <jogo@openwrt.org>
   3 Date: Tue, 16 Jun 2015 13:15:08 +0200
   4 Subject: [PATCH] phy/mdio-bitbang: prevent rescheduling during command
   5
   6 It seems some phys have some maximum timings for accessing the MDIO line,
   7 resulting in bit errors under cpu stress. Prevent this from happening by
   8 disabling interrupts when sending commands.
   9
  10 Signed-off-by: Jonas Gorski <jogo@openwrt.org>
  11 ---
  12  drivers/net/phy/mdio-bitbang.c | 9 +++++++++
  13  1 file changed, 9 insertions(+)
  14
  15 --- a/drivers/net/phy/mdio-bitbang.c
  16 +++ b/drivers/net/phy/mdio-bitbang.c
  17 @@ -17,6 +17,7 @@
  18   * kind, whether express or implied.
  19   */
  20
  21 +#include <linux/irqflags.h>
  22  #include <linux/module.h>
  23  #include <linux/mdio-bitbang.h>
  24  #include <linux/types.h>
  25 @@ -156,7 +157,9 @@ static int mdiobb_read(struct mii_bus *b
  26  {
  27         struct mdiobb_ctrl *ctrl = bus->priv;
  28         int ret, i;
  29 +       long flags;
  30
  31 +       local_irq_save(flags);
  32         if (reg & MII_ADDR_C45) {
  33                 reg = mdiobb_cmd_addr(ctrl, phy, reg);
  34                 mdiobb_cmd(ctrl, MDIO_C45_READ, phy, reg);
  35 @@ -169,13 +172,17 @@ static int mdiobb_read(struct mii_bus *b
  36
  37         ret = mdiobb_get_num(ctrl, 16);
  38         mdiobb_get_bit(ctrl);
  39 +       local_irq_restore(flags);
  40 +
  41         return ret;
  42  }
  43
  44  static int mdiobb_write(struct mii_bus *bus, int phy, int reg, u16 val)
  45  {
  46         struct mdiobb_ctrl *ctrl = bus->priv;
  47 +       long flags;
  48
  49 +       local_irq_save(flags);
  50         if (reg & MII_ADDR_C45) {
  51                 reg = mdiobb_cmd_addr(ctrl, phy, reg);
  52                 mdiobb_cmd(ctrl, MDIO_C45_WRITE, phy, reg);
  53 @@ -190,6 +197,8 @@ static int mdiobb_write(struct mii_bus *
  54
  55         ctrl->ops->set_mdio_dir(ctrl, 0);
  56         mdiobb_get_bit(ctrl);
  57 +       local_irq_restore(flags);
  58 +
  59         return 0;
  60  }
  61