sfc: Clean up MDIO flag setting

We often want to set or clear a flag in an MDIO register, but avoid
writing if no change is required since this can have side-effects.
Encapsulate this in a function, mdio_clause45_set_flag().

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 32 insertions, 59 deletions

diff --git a/drivers/net/sfc/mdio_10g.c b/drivers/net/sfc/mdio_10g.c
index 1eed48407ed8..8d91131aa5ab 100644
--- a/drivers/net/sfc/mdio_10g.c
+++ b/drivers/net/sfc/mdio_10g.c
@@ -205,61 +205,24 @@ bool mdio_clause45_links_ok(struct efx_nic *efx, unsigned int mmd_mask)
 
 void mdio_clause45_transmit_disable(struct efx_nic *efx)
 {
-        int phy_id = efx->mii.phy_id;
-        int ctrl1, ctrl2;
-
-        ctrl1 = ctrl2 = mdio_clause45_read(efx, phy_id, MDIO_MMD_PMAPMD,
-                                           MDIO_MMDREG_TXDIS);
-        if (efx->phy_mode & PHY_MODE_TX_DISABLED)
-                ctrl2 |= (1 << MDIO_MMDREG_TXDIS_GLOBAL_LBN);
-        else
-                ctrl1 &= ~(1 << MDIO_MMDREG_TXDIS_GLOBAL_LBN);
-        if (ctrl1 != ctrl2)
-                mdio_clause45_write(efx, phy_id, MDIO_MMD_PMAPMD,
-                                    MDIO_MMDREG_TXDIS, ctrl2);
+        mdio_clause45_set_flag(efx, efx->mii.phy_id, MDIO_MMD_PMAPMD,
+                               MDIO_MMDREG_TXDIS, MDIO_MMDREG_TXDIS_GLOBAL_LBN,
+                               efx->phy_mode & PHY_MODE_TX_DISABLED);
 }
 
 void mdio_clause45_phy_reconfigure(struct efx_nic *efx)
 {
         int phy_id = efx->mii.phy_id;
-        int ctrl1, ctrl2;
-
-        /* Handle (with debouncing) PMA/PMD loopback */
-        ctrl1 = ctrl2 = mdio_clause45_read(efx, phy_id, MDIO_MMD_PMAPMD,
-                                           MDIO_MMDREG_CTRL1);
-
-        if (efx->loopback_mode == LOOPBACK_PMAPMD)
-                ctrl2 |= (1 << MDIO_PMAPMD_CTRL1_LBACK_LBN);
-        else
-                ctrl2 &= ~(1 << MDIO_PMAPMD_CTRL1_LBACK_LBN);
-
-        if (ctrl1 != ctrl2)
-                mdio_clause45_write(efx, phy_id, MDIO_MMD_PMAPMD,
-                                    MDIO_MMDREG_CTRL1, ctrl2);
-
-        /* Handle (with debouncing) PCS loopback */
-        ctrl1 = ctrl2 = mdio_clause45_read(efx, phy_id, MDIO_MMD_PCS,
-                                           MDIO_MMDREG_CTRL1);
-        if (efx->loopback_mode == LOOPBACK_PCS)
-                ctrl2 |= (1 << MDIO_MMDREG_CTRL1_LBACK_LBN);
-        else
-                ctrl2 &= ~(1 << MDIO_MMDREG_CTRL1_LBACK_LBN);
 
-        if (ctrl1 != ctrl2)
-                mdio_clause45_write(efx, phy_id, MDIO_MMD_PCS,
-                                    MDIO_MMDREG_CTRL1, ctrl2);
-
-        /* Handle (with debouncing) PHYXS network loopback */
-        ctrl1 = ctrl2 = mdio_clause45_read(efx, phy_id, MDIO_MMD_PHYXS,
-                                           MDIO_MMDREG_CTRL1);
-        if (efx->loopback_mode == LOOPBACK_NETWORK)
-                ctrl2 |= (1 << MDIO_MMDREG_CTRL1_LBACK_LBN);
-        else
-                ctrl2 &= ~(1 << MDIO_MMDREG_CTRL1_LBACK_LBN);
-
-        if (ctrl1 != ctrl2)
-                mdio_clause45_write(efx, phy_id, MDIO_MMD_PHYXS,
-                                    MDIO_MMDREG_CTRL1, ctrl2);
+        mdio_clause45_set_flag(efx, phy_id, MDIO_MMD_PMAPMD,
+                               MDIO_MMDREG_CTRL1, MDIO_PMAPMD_CTRL1_LBACK_LBN,
+                               efx->loopback_mode == LOOPBACK_PMAPMD);
+        mdio_clause45_set_flag(efx, phy_id, MDIO_MMD_PCS,
+                               MDIO_MMDREG_CTRL1, MDIO_MMDREG_CTRL1_LBACK_LBN,
+                               efx->loopback_mode == LOOPBACK_PCS);
+        mdio_clause45_set_flag(efx, phy_id, MDIO_MMD_PHYXS,
+                               MDIO_MMDREG_CTRL1, MDIO_MMDREG_CTRL1_LBACK_LBN,
+                               efx->loopback_mode == LOOPBACK_NETWORK);
 }
 
 static void mdio_clause45_set_mmd_lpower(struct efx_nic *efx,
@@ -267,21 +230,13 @@ static void mdio_clause45_set_mmd_lpower(struct efx_nic *efx,
 {
         int phy = efx->mii.phy_id;
         int stat = mdio_clause45_read(efx, phy, mmd, MDIO_MMDREG_STAT1);
-        int ctrl1, ctrl2;
 
         EFX_TRACE(efx, "Setting low power mode for MMD %d to %d\n",
                   mmd, lpower);
 
         if (stat & (1 << MDIO_MMDREG_STAT1_LPABLE_LBN)) {
-                ctrl1 = ctrl2 = mdio_clause45_read(efx, phy,
-                                                   mmd, MDIO_MMDREG_CTRL1);
-                if (lpower)
-                        ctrl2 |= (1 << MDIO_MMDREG_CTRL1_LPOWER_LBN);
-                else
-                        ctrl2 &= ~(1 << MDIO_MMDREG_CTRL1_LPOWER_LBN);
-                if (ctrl1 != ctrl2)
-                        mdio_clause45_write(efx, phy, mmd,
-                                            MDIO_MMDREG_CTRL1, ctrl2);
+                mdio_clause45_set_flag(efx, phy, mmd, MDIO_MMDREG_CTRL1,
+                                       MDIO_MMDREG_CTRL1_LPOWER_LBN, lpower);
         }
 }
 
@@ -395,3 +350,17 @@ int mdio_clause45_set_settings(struct efx_nic *efx,
                 return 0;
         return -EOPNOTSUPP;
 }
+
+void mdio_clause45_set_flag(struct efx_nic *efx, u8 prt, u8 dev,
+                            u16 addr, int bit, bool sense)
+{
+        int old_val = mdio_clause45_read(efx, prt, dev, addr);
+        int new_val;
+
+        if (sense)
+                new_val = old_val | (1 << bit);
+        else
+                new_val = old_val & ~(1 << bit);
+        if (old_val != new_val)
+                mdio_clause45_write(efx, prt, dev, addr, new_val);
+}
diff --git a/drivers/net/sfc/mdio_10g.h b/drivers/net/sfc/mdio_10g.h
index 45163838130e..4830e0c1da0b 100644
--- a/drivers/net/sfc/mdio_10g.h
+++ b/drivers/net/sfc/mdio_10g.h
@@ -259,4 +259,8 @@ extern int mdio_clause45_set_settings(struct efx_nic *efx,
 extern int mdio_clause45_wait_reset_mmds(struct efx_nic *efx,
                                          unsigned int mmd_mask);
 
+/* Set or clear flag, debouncing */
+extern void mdio_clause45_set_flag(struct efx_nic *efx, u8 prt, u8 dev,
+                                   u16 addr, int bit, bool sense);
+
 #endif /* EFX_MDIO_10G_H */