1 From b3797d1a92afe97c173b00fdb7824cedba24eef0 Mon Sep 17 00:00:00 2001
2 From: Chuanhong Guo <gch981213@gmail.com>
3 Date: Sun, 20 Sep 2020 01:00:45 +0800
4 Subject: [PATCH] ath79: ar8216: make switch register access atomic
6 due to some unknown reason these register accesses sometimes fail
7 on the integrated switch without this patch.
9 THIS ONLY WORKS ON ATH79 AND MAY BREAK THE DRIVER ON OTHER PLATFORMS!
10 The mdio bus on ath79 works in polling mode and doesn't rely on
11 any interrupt. This patch breaks the driver on any mdio master
15 --- a/drivers/net/phy/ar8216.c
16 +++ b/drivers/net/phy/ar8216.c
17 @@ -252,6 +252,7 @@ ar8xxx_mii_write32(struct ar8xxx_priv *p
19 ar8xxx_read(struct ar8xxx_priv *priv, int reg)
21 + unsigned long flags;
22 struct mii_bus *bus = priv->mii_bus;
25 @@ -259,11 +260,13 @@ ar8xxx_read(struct ar8xxx_priv *priv, in
26 split_addr((u32) reg, &r1, &r2, &page);
28 mutex_lock(&bus->mdio_lock);
29 + local_irq_save(flags);
31 bus->write(bus, 0x18, 0, page);
32 wait_for_page_switch();
33 val = ar8xxx_mii_read32(priv, 0x10 | r2, r1);
35 + local_irq_restore(flags);
36 mutex_unlock(&bus->mdio_lock);
39 @@ -272,17 +275,20 @@ ar8xxx_read(struct ar8xxx_priv *priv, in
41 ar8xxx_write(struct ar8xxx_priv *priv, int reg, u32 val)
43 + unsigned long flags;
44 struct mii_bus *bus = priv->mii_bus;
47 split_addr((u32) reg, &r1, &r2, &page);
49 mutex_lock(&bus->mdio_lock);
50 + local_irq_save(flags);
52 bus->write(bus, 0x18, 0, page);
53 wait_for_page_switch();
54 ar8xxx_mii_write32(priv, 0x10 | r2, r1, val);
56 + local_irq_restore(flags);
57 mutex_unlock(&bus->mdio_lock);