net: dsa: microchip: correct KSZ8795 static MAC table access

commit 4bdf79d686b49ac49373b36466acfb93972c7d7c upstream.

The KSZ8795 driver code was modified to use on KSZ8863/73, which has
different register definitions.  Some of the new KSZ8795 register
information are wrong compared to previous code.

KSZ8795 also behaves differently in that the STATIC_MAC_TABLE_USE_FID
and STATIC_MAC_TABLE_FID bits are off by 1 when doing MAC table reading
than writing.  To compensate that a special code was added to shift the
register value by 1 before applying those bits.  This is wrong when the
code is running on KSZ8863, so this special code is only executed when
KSZ8795 is detected.

Fixes: 4b20a07e103f ("net: dsa: microchip: ksz8795: add support for ksz88xx chips")
Signed-off-by: Tristram Ha <Tristram.Ha@microchip.com>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jörg Sommer <joerg@jo-so.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index c5142f86a3c755577ec75729d46464a9d9ffac48..ef88e26aedf264e05f66083ebc1511681fa213c8 100644 (file)
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -25,6 +25,8 @@
 #include "ksz8795_reg.h"
 #include "ksz8.h"
 
+#define KSZ8795_CHIP_ID         0x09
+
 static const u8 ksz8795_regs[] = {
        [REG_IND_CTRL_0]                = 0x6E,
        [REG_IND_DATA_8]                = 0x70,
@@ -52,13 +54,13 @@ static const u32 ksz8795_masks[] = {
        [STATIC_MAC_TABLE_VALID]        = BIT(21),
        [STATIC_MAC_TABLE_USE_FID]      = BIT(23),
        [STATIC_MAC_TABLE_FID]          = GENMASK(30, 24),
-       [STATIC_MAC_TABLE_OVERRIDE]     = BIT(26),
-       [STATIC_MAC_TABLE_FWD_PORTS]    = GENMASK(24, 20),
+       [STATIC_MAC_TABLE_OVERRIDE]     = BIT(22),
+       [STATIC_MAC_TABLE_FWD_PORTS]    = GENMASK(20, 16),
        [DYNAMIC_MAC_TABLE_ENTRIES_H]   = GENMASK(6, 0),
-       [DYNAMIC_MAC_TABLE_MAC_EMPTY]   = BIT(8),
+       [DYNAMIC_MAC_TABLE_MAC_EMPTY]   = BIT(7),
        [DYNAMIC_MAC_TABLE_NOT_READY]   = BIT(7),
        [DYNAMIC_MAC_TABLE_ENTRIES]     = GENMASK(31, 29),
-       [DYNAMIC_MAC_TABLE_FID]         = GENMASK(26, 20),
+       [DYNAMIC_MAC_TABLE_FID]         = GENMASK(22, 16),
        [DYNAMIC_MAC_TABLE_SRC_PORT]    = GENMASK(26, 24),
        [DYNAMIC_MAC_TABLE_TIMESTAMP]   = GENMASK(28, 27),
 };
@@ -601,7 +603,13 @@ static int ksz8_r_sta_mac_table(struct ksz_device *dev, u16 addr,
                                shifts[STATIC_MAC_FWD_PORTS];
                alu->is_override =
                        (data_hi & masks[STATIC_MAC_TABLE_OVERRIDE]) ? 1 : 0;
-               data_hi >>= 1;
+
+               /* KSZ8795 family switches have STATIC_MAC_TABLE_USE_FID and
+                * STATIC_MAC_TABLE_FID definitions off by 1 when doing read on the
+                * static MAC table compared to doing write.
+                */
+               if (dev->chip_id == KSZ8795_CHIP_ID)
+                       data_hi >>= 1;
                alu->is_static = true;
                alu->is_use_fid =
                        (data_hi & masks[STATIC_MAC_TABLE_USE_FID]) ? 1 : 0;