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From: Biju Das <biju.das.jz@bp.renesas.com>
To: cip-dev@lists.cip-project.org,
	Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>,
	Pavel Machek <pavel@denx.de>
Cc: Biju Das <biju.das.jz@bp.renesas.com>,
	Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: [PATCH 4.19.y-cip] ravb: remove undocumented counter processing
Date: Mon,  5 Feb 2024 09:02:49 +0000	[thread overview]
Message-ID: <20240205090249.34569-1-biju.das.jz@bp.renesas.com> (raw)

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/OS0PR01MB638896E67835B158BC93D8C592422@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 --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
index f17e7948444a..7ad35954a332 100644
--- a/drivers/net/ethernet/renesas/ravb.h
+++ b/drivers/net/ethernet/renesas/ravb.h
@@ -194,15 +194,11 @@ 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 2cd14c37c36d..d9b31d49321b 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1656,15 +1656,6 @@ 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;
-- 
2.25.1



             reply	other threads:[~2024-02-05  9:03 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-02-05  9:02 Biju Das [this message]
2024-02-05  9:03 [PATCH 4.19.y-cip] ravb: remove undocumented counter processing Biju Das
2024-02-06 10:53 ` Pavel Machek
2024-02-06 23:57   ` nobuhiro1.iwamatsu
2024-02-07 10:21     ` Pavel Machek

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