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authorMarc Kleine-Budde <mkl@pengutronix.de>2013-10-04 12:52:36 +0400
committerMarc Kleine-Budde <mkl@pengutronix.de>2013-10-10 01:01:35 +0400
commitd5a7b406c529e4595ce03dc8f6dcf7fa36f106fa (patch)
treeb53ac411845daaedd3e2d287974301eea1b36a01 /drivers/net/can/flexcan.c
parent87b0a0b5c46aea63cdc5c5d788fe2c91406e3161 (diff)
downloadlinux-d5a7b406c529e4595ce03dc8f6dcf7fa36f106fa.tar.xz
can: flexcan: flexcan_chip_start: fix regression, mark one MB for TX and abort pending TX
In patch 0d1862e can: flexcan: fix flexcan_chip_start() on imx6 the loop in flexcan_chip_start() that iterates over all mailboxes after the soft reset of the CAN core was removed. This loop put all mailboxes (even the ones marked as reserved 1...7) into EMPTY/INACTIVE mode. On mailboxes 8...63, this aborts any pending TX messages. After a cold boot there is random garbage in the mailboxes, which leads to spontaneous transmit of CAN frames during first activation. Further if the interface was disabled with a pending message (usually due to an error condition on the CAN bus), this message is retransmitted after enabling the interface again. This patch fixes the regression by: 1) Limiting the maximum number of used mailboxes to 8, 0...7 are used by the RX FIFO, 8 is used by TX. 2) Marking the TX mailbox as EMPTY/INACTIVE, so that any pending TX of that mailbox is aborted. Cc: linux-stable <stable@vger.kernel.org> Cc: Lothar Waßmann <LW@KARO-electronics.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/flexcan.c')
-rw-r--r--drivers/net/can/flexcan.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 3f21142138b7..f028c5d52e21 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -62,7 +62,7 @@
#define FLEXCAN_MCR_BCC BIT(16)
#define FLEXCAN_MCR_LPRIO_EN BIT(13)
#define FLEXCAN_MCR_AEN BIT(12)
-#define FLEXCAN_MCR_MAXMB(x) ((x) & 0xf)
+#define FLEXCAN_MCR_MAXMB(x) ((x) & 0x1f)
#define FLEXCAN_MCR_IDAM_A (0 << 8)
#define FLEXCAN_MCR_IDAM_B (1 << 8)
#define FLEXCAN_MCR_IDAM_C (2 << 8)
@@ -735,9 +735,11 @@ static int flexcan_chip_start(struct net_device *dev)
*
*/
reg_mcr = flexcan_read(&regs->mcr);
+ reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN |
- FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS;
+ FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS |
+ FLEXCAN_MCR_MAXMB(FLEXCAN_TX_BUF_ID);
netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
flexcan_write(reg_mcr, &regs->mcr);
@@ -771,6 +773,10 @@ static int flexcan_chip_start(struct net_device *dev)
netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
flexcan_write(reg_ctrl, &regs->ctrl);
+ /* Abort any pending TX, mark Mailbox as INACTIVE */
+ flexcan_write(FLEXCAN_MB_CNT_CODE(0x4),
+ &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
+
/* acceptance mask/acceptance code (accept everything) */
flexcan_write(0x0, &regs->rxgmask);
flexcan_write(0x0, &regs->rx14mask);