netdev - [PATCH net 5/7] can: kvaser_pciefd: Do not send EFLUSH command on TFD interrupt

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230518073241.1110453-6-mkl@pengutronix.de>
Date: Thu, 18 May 2023 09:32:39 +0200
From: Marc Kleine-Budde <mkl@...gutronix.de>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net,
	kuba@...nel.org,
	linux-can@...r.kernel.org,
	kernel@...gutronix.de,
	Jimmy Assarsson <extja@...ser.com>,
	stable@...r.kernel.org,
	Marc Kleine-Budde <mkl@...gutronix.de>
Subject: [PATCH net 5/7] can: kvaser_pciefd: Do not send EFLUSH command on TFD interrupt

From: Jimmy Assarsson <extja@...ser.com>

Under certain circumstances we send two EFLUSH commands, resulting in two
EFLUSH ack packets, while only expecting a single EFLUSH ack.
This can cause the driver Tx flush completion to get out of sync.

To avoid this problem, don't enable the "Transmit buffer flush done" (TFD)
interrupt and remove the code handling it.
Now we only send EFLUSH command after receiving status packet with
"Init detected" (IDET) bit set.

Fixes: 26ad340e582d ("can: kvaser_pciefd: Add driver for Kvaser PCIEcan devices")
Cc: stable@...r.kernel.org
Signed-off-by: Jimmy Assarsson <extja@...ser.com>
Link: https://lore.kernel.org/r/20230516134318.104279-6-extja@kvaser.com
Signed-off-by: Marc Kleine-Budde <mkl@...gutronix.de>
---
 drivers/net/can/kvaser_pciefd.c | 21 ++++-----------------
 1 file changed, 4 insertions(+), 17 deletions(-)

diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
index 0e03c1cd47b3..4fafb7658349 100644
--- a/drivers/net/can/kvaser_pciefd.c
+++ b/drivers/net/can/kvaser_pciefd.c
@@ -531,7 +531,7 @@ static int kvaser_pciefd_set_tx_irq(struct kvaser_pciefd_can *can)
 	      KVASER_PCIEFD_KCAN_IRQ_TOF | KVASER_PCIEFD_KCAN_IRQ_ABD |
 	      KVASER_PCIEFD_KCAN_IRQ_TAE | KVASER_PCIEFD_KCAN_IRQ_TAL |
 	      KVASER_PCIEFD_KCAN_IRQ_FDIC | KVASER_PCIEFD_KCAN_IRQ_BPP |
-	      KVASER_PCIEFD_KCAN_IRQ_TAR | KVASER_PCIEFD_KCAN_IRQ_TFD;
+	      KVASER_PCIEFD_KCAN_IRQ_TAR;
 
 	iowrite32(msk, can->reg_base + KVASER_PCIEFD_KCAN_IEN_REG);
 
@@ -579,7 +579,7 @@ static void kvaser_pciefd_start_controller_flush(struct kvaser_pciefd_can *can)
 
 	spin_lock_irqsave(&can->lock, irq);
 	iowrite32(-1, can->reg_base + KVASER_PCIEFD_KCAN_IRQ_REG);
-	iowrite32(KVASER_PCIEFD_KCAN_IRQ_ABD | KVASER_PCIEFD_KCAN_IRQ_TFD,
+	iowrite32(KVASER_PCIEFD_KCAN_IRQ_ABD,
 		  can->reg_base + KVASER_PCIEFD_KCAN_IEN_REG);
 
 	status = ioread32(can->reg_base + KVASER_PCIEFD_KCAN_STAT_REG);
@@ -622,7 +622,7 @@ static int kvaser_pciefd_bus_on(struct kvaser_pciefd_can *can)
 	iowrite32(0, can->reg_base + KVASER_PCIEFD_KCAN_IEN_REG);
 	iowrite32(-1, can->reg_base + KVASER_PCIEFD_KCAN_IRQ_REG);
 
-	iowrite32(KVASER_PCIEFD_KCAN_IRQ_ABD | KVASER_PCIEFD_KCAN_IRQ_TFD,
+	iowrite32(KVASER_PCIEFD_KCAN_IRQ_ABD,
 		  can->reg_base + KVASER_PCIEFD_KCAN_IEN_REG);
 
 	mode = ioread32(can->reg_base + KVASER_PCIEFD_KCAN_MODE_REG);
@@ -1015,8 +1015,7 @@ static int kvaser_pciefd_setup_can_ctrls(struct kvaser_pciefd *pcie)
 		SET_NETDEV_DEV(netdev, &pcie->pci->dev);
 
 		iowrite32(-1, can->reg_base + KVASER_PCIEFD_KCAN_IRQ_REG);
-		iowrite32(KVASER_PCIEFD_KCAN_IRQ_ABD |
-			  KVASER_PCIEFD_KCAN_IRQ_TFD,
+		iowrite32(KVASER_PCIEFD_KCAN_IRQ_ABD,
 			  can->reg_base + KVASER_PCIEFD_KCAN_IEN_REG);
 
 		pcie->can[i] = can;
@@ -1443,9 +1442,6 @@ static int kvaser_pciefd_handle_status_packet(struct kvaser_pciefd *pcie,
 		cmd = KVASER_PCIEFD_KCAN_CMD_AT;
 		cmd |= ++can->cmd_seq << KVASER_PCIEFD_KCAN_CMD_SEQ_SHIFT;
 		iowrite32(cmd, can->reg_base + KVASER_PCIEFD_KCAN_CMD_REG);
-
-		iowrite32(KVASER_PCIEFD_KCAN_IRQ_TFD,
-			  can->reg_base + KVASER_PCIEFD_KCAN_IEN_REG);
 	} else if (p->header[0] & KVASER_PCIEFD_SPACK_IDET &&
 		   p->header[0] & KVASER_PCIEFD_SPACK_IRM &&
 		   cmdseq == (p->header[1] & KVASER_PCIEFD_PACKET_SEQ_MSK) &&
@@ -1732,15 +1728,6 @@ static int kvaser_pciefd_transmit_irq(struct kvaser_pciefd_can *can)
 	if (irq & KVASER_PCIEFD_KCAN_IRQ_TOF)
 		netdev_err(can->can.dev, "Tx FIFO overflow\n");
 
-	if (irq & KVASER_PCIEFD_KCAN_IRQ_TFD) {
-		u8 count = ioread32(can->reg_base +
-				    KVASER_PCIEFD_KCAN_TX_NPACKETS_REG) & 0xff;
-
-		if (count == 0)
-			iowrite32(KVASER_PCIEFD_KCAN_CTRL_EFLUSH,
-				  can->reg_base + KVASER_PCIEFD_KCAN_CTRL_REG);
-	}
-
 	if (irq & KVASER_PCIEFD_KCAN_IRQ_BPP)
 		netdev_err(can->can.dev,
 			   "Fail to change bittiming, when not in reset mode\n");
-- 
2.39.2