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[4.4.y-cip] ravb: remove undocumented counter processing

Message ID 20240205082753.17776-1-biju.das.jz@bp.renesas.com (mailing list archive)
State Accepted
Headers show
Series [4.4.y-cip] ravb: remove undocumented counter processing | expand

Commit Message

Biju Das Feb. 5, 2024, 8:27 a.m. UTC 
From: Simon Horman <horms+renesas@verge.net.au>

commit 009a470365b37106bbd66f1e1a53bc6c3c0072bc upstream.

This patch removes the use of the undocumented counter registers
CDCR, LCCR, CERCR, CEECR.

Offsets used for undocumented registers are considered reserved and
should not be written to. After some internal investigation with Renesas
it remains unclear why this driver accesses these fields but regardless of
what the historical reasons are the current code is considered incorrect.

Based on work by Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
Note:
 This patch is depend upon[1]
 [1] https://lore.kernel.org/cip-dev/OS0PR01MB6388993D6F46E71E12707AE292422@OS0PR01MB6388.jpnprd01.prod.outlook.com/T/#t
---
 drivers/net/ethernet/renesas/ravb.h      | 4 ----
 drivers/net/ethernet/renesas/ravb_main.c | 9 ---------
 2 files changed, 13 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index 0623fff932e4..c8654cd1409f 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -186,15 +186,11 @@  enum ravb_reg {
 	MAHR	= 0x05c0,
 	MALR	= 0x05c8,
 	TROCR	= 0x0700,	/* Undocumented? */
-	CDCR	= 0x0708,	/* Undocumented? */
-	LCCR	= 0x0710,	/* Undocumented? */
 	CEFCR	= 0x0740,
 	FRECR	= 0x0748,
 	TSFRCR	= 0x0750,
 	TLFRCR	= 0x0758,
 	RFCR	= 0x0760,
-	CERCR	= 0x0768,	/* Undocumented? */
-	CEECR	= 0x0770,	/* Undocumented? */
 	MAFCR	= 0x0778,
 };
 
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 8948d659d1af..fe67f02a9323 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1476,15 +1476,6 @@  static struct net_device_stats *ravb_get_stats(struct net_device *ndev)
 
 	nstats->tx_dropped += ravb_read(ndev, TROCR);
 	ravb_write(ndev, 0, TROCR);	/* (write clear) */
-	nstats->collisions += ravb_read(ndev, CDCR);
-	ravb_write(ndev, 0, CDCR);	/* (write clear) */
-	nstats->tx_carrier_errors += ravb_read(ndev, LCCR);
-	ravb_write(ndev, 0, LCCR);	/* (write clear) */
-
-	nstats->tx_carrier_errors += ravb_read(ndev, CERCR);
-	ravb_write(ndev, 0, CERCR);	/* (write clear) */
-	nstats->tx_carrier_errors += ravb_read(ndev, CEECR);
-	ravb_write(ndev, 0, CEECR);	/* (write clear) */
 
 	nstats->rx_packets = stats0->rx_packets + stats1->rx_packets;
 	nstats->tx_packets = stats0->tx_packets + stats1->tx_packets;