From: Marc Kleine-Budde Date: Fri, 4 Oct 2013 08:52:36 +0000 (+0200) Subject: can: flexcan: flexcan_chip_start: fix regression, mark one MB for TX and abort pending TX X-Git-Tag: firefly_0821_release~6453^2~391 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=d60241f65bdc363f1be2b099bd98ff13a96c1f0d;p=firefly-linux-kernel-4.4.55.git can: flexcan: flexcan_chip_start: fix regression, mark one MB for TX and abort pending TX 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 --- diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 261d1ee64473..a8f33a525dd6 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -63,7 +63,7 @@ #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) @@ -745,9 +745,11 @@ static int flexcan_chip_start(struct net_device *dev) * */ reg_mcr = flexcan_read(®s->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, ®s->mcr); @@ -792,6 +794,10 @@ static int flexcan_chip_start(struct net_device *dev) ®s->cantxfg[i].can_ctrl); } + /* Abort any pending TX, mark Mailbox as INACTIVE */ + flexcan_write(FLEXCAN_MB_CNT_CODE(0x4), + ®s->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl); + /* acceptance mask/acceptance code (accept everything) */ flexcan_write(0x0, ®s->rxgmask); flexcan_write(0x0, ®s->rx14mask);