[PATCH 3.4 09/26] can: flexcan: flexcan_chip_start: fix regression, mark one MB for TX and abort pending TX
3.4-stable review patch. If anyone has any objections, please let me know. -- From: Marc Kleine-Budde commit d5a7b406c529e4595ce03dc8f6dcf7fa36f106fa upstream. 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: Lothar Waßmann Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- drivers/net/can/flexcan.c | 10 -- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -60,7 +60,7 @@ #define FLEXCAN_MCR_BCCBIT(16) #define FLEXCAN_MCR_LPRIO_EN BIT(13) #define FLEXCAN_MCR_AENBIT(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) @@ -701,9 +701,11 @@ static int flexcan_chip_start(struct net * */ reg_mcr = flexcan_read(>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, >mcr); @@ -744,6 +746,10 @@ static int flexcan_chip_start(struct net >cantxfg[i].can_ctrl); } + /* Abort any pending TX, mark Mailbox as INACTIVE */ + flexcan_write(FLEXCAN_MB_CNT_CODE(0x4), + >cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); + /* acceptance mask/acceptance code (accept everything) */ flexcan_write(0x0, >rxgmask); flexcan_write(0x0, >rx14mask); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3.4 09/26] can: flexcan: flexcan_chip_start: fix regression, mark one MB for TX and abort pending TX
3.4-stable review patch. If anyone has any objections, please let me know. -- From: Marc Kleine-Budde m...@pengutronix.de commit d5a7b406c529e4595ce03dc8f6dcf7fa36f106fa upstream. 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: Lothar Waßmann l...@karo-electronics.de Signed-off-by: Marc Kleine-Budde m...@pengutronix.de Signed-off-by: Greg Kroah-Hartman gre...@linuxfoundation.org --- drivers/net/can/flexcan.c | 10 -- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -60,7 +60,7 @@ #define FLEXCAN_MCR_BCCBIT(16) #define FLEXCAN_MCR_LPRIO_EN BIT(13) #define FLEXCAN_MCR_AENBIT(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) @@ -701,9 +701,11 @@ static int flexcan_chip_start(struct net * */ 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); @@ -744,6 +746,10 @@ static int flexcan_chip_start(struct net regs-cantxfg[i].can_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); -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
