target/linux/ath79/patches-4.14/901-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 Index: linux-4.14.18/drivers/net/phy/mdio-bitbang.c
  16 ===================================================================
  17 --- linux-4.14.18.orig/drivers/net/phy/mdio-bitbang.c
  18 +++ linux-4.14.18/drivers/net/phy/mdio-bitbang.c
  19 @@ -17,6 +17,7 @@
  20   * kind, whether express or implied.
  21   */
  22
  23 +#include <linux/irqflags.h>
  24  #include <linux/module.h>
  25  #include <linux/mdio-bitbang.h>
  26  #include <linux/types.h>
  27 @@ -156,7 +157,9 @@ static int mdiobb_read(struct mii_bus *b
  28  {
  29         struct mdiobb_ctrl *ctrl = bus->priv;
  30         int ret;
  31 +       unsigned long flags;
  32
  33 +       local_irq_save(flags);
  34         if (reg & MII_ADDR_C45) {
  35                 reg = mdiobb_cmd_addr(ctrl, phy, reg);
  36                 mdiobb_cmd(ctrl, MDIO_C45_READ, phy, reg);
  37 @@ -169,13 +172,17 @@ static int mdiobb_read(struct mii_bus *b
  38
  39         ret = mdiobb_get_num(ctrl, 16);
  40         mdiobb_get_bit(ctrl);
  41 +       local_irq_restore(flags);
  42 +
  43         return ret;
  44  }
  45
  46  static int mdiobb_write(struct mii_bus *bus, int phy, int reg, u16 val)
  47  {
  48         struct mdiobb_ctrl *ctrl = bus->priv;
  49 +       unsigned long flags;
  50
  51 +       local_irq_save(flags);
  52         if (reg & MII_ADDR_C45) {
  53                 reg = mdiobb_cmd_addr(ctrl, phy, reg);
  54                 mdiobb_cmd(ctrl, MDIO_C45_WRITE, phy, reg);
  55 @@ -190,6 +197,8 @@ static int mdiobb_write(struct mii_bus *
  56
  57         ctrl->ops->set_mdio_dir(ctrl, 0);
  58         mdiobb_get_bit(ctrl);
  59 +       local_irq_restore(flags);
  60 +
  61         return 0;
  62  }
  63