From: "Ahmed S. Darwish" <[email protected]>

v4.19.135-rt61-rc1 stable review patch.
If anyone has any objections, please let me know.

-----------


[ Upstream commit 6554eac9ef2bd1c968886b31cc7266b49258a463 ]

Commit bf7afb29d545 ("phy: improve safety of fixed-phy MII register
reading") protected the fixed PHY status with a sequence counter.

Two years later, commit d2b977939b18 ("net: phy: fixed-phy: remove
fixed_phy_update_state()") removed the sequence counter's write side
critical section -- neutralizing its read side retry loop.

Remove the unused seqcount.

Signed-off-by: Ahmed S. Darwish <[email protected]>
Reviewed-by: Sebastian Andrzej Siewior <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
(cherry picked from v5.8-rc1 commit 79cbb6bc3332da7162c2581e151659ab8ebaa528)
Signed-off-by: Ahmed S. Darwish <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Tom Zanussi <[email protected]>
---
 drivers/net/phy/fixed_phy.c | 25 +++++++++----------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/drivers/net/phy/fixed_phy.c b/drivers/net/phy/fixed_phy.c
index 59820164502e..953ff54dd5df 100644
--- a/drivers/net/phy/fixed_phy.c
+++ b/drivers/net/phy/fixed_phy.c
@@ -23,7 +23,6 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/gpio.h>
-#include <linux/seqlock.h>
 #include <linux/idr.h>
 
 #include "swphy.h"
@@ -36,7 +35,6 @@ struct fixed_mdio_bus {
 struct fixed_phy {
        int addr;
        struct phy_device *phydev;
-       seqcount_t seqcount;
        struct fixed_phy_status status;
        int (*link_update)(struct net_device *, struct fixed_phy_status *);
        struct list_head node;
@@ -62,18 +60,15 @@ static int fixed_mdio_read(struct mii_bus *bus, int 
phy_addr, int reg_num)
        list_for_each_entry(fp, &fmb->phys, node) {
                if (fp->addr == phy_addr) {
                        struct fixed_phy_status state;
-                       int s;
-
-                       do {
-                               s = read_seqcount_begin(&fp->seqcount);
-                               /* Issue callback if user registered it. */
-                               if (fp->link_update)
-                                       
fp->link_update(fp->phydev->attached_dev,
-                                                       &fp->status);
-                               /* Check the GPIO for change in status */
-                               fixed_phy_update(fp);
-                               state = fp->status;
-                       } while (read_seqcount_retry(&fp->seqcount, s));
+
+                       /* Issue callback if user registered it. */
+                       if (fp->link_update)
+                               fp->link_update(fp->phydev->attached_dev,
+                                               &fp->status);
+
+                       /* Check the GPIO for change in status */
+                       fixed_phy_update(fp);
+                       state = fp->status;
 
                        return swphy_read_reg(reg_num, &state);
                }
@@ -131,8 +126,6 @@ int fixed_phy_add(unsigned int irq, int phy_addr,
        if (!fp)
                return -ENOMEM;
 
-       seqcount_init(&fp->seqcount);
-
        if (irq != PHY_POLL)
                fmb->mii_bus->irq[phy_addr] = irq;
 
-- 
2.17.1

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