[PATCH v3 1/2] can: flexcan: Correctly initialize mailboxes

[Marc Kleine-Budde]

From: David Jander <***@protonic.nl>

Apparently mailboxes may contain random data at startup, causing some of
them being prepared for message reception. This causes overruns being
missed or even confusing the IRQ check for trasmitted messages, increasing
the transmit counter instead of the error counter.

Signed-off-by: David Jander <***@protonic.nl>
Signed-off-by: Marc Kleine-Budde <***@pengutronix.de>
---
Changes since v2:
- move before FLEXCAN_TX_BUF_ID
- start loop at FLEXCAN_TX_BUF_ID

Changes since v1:
- don't remove existing initialization of FLEXCAN_TX_BUF_ID
- start loop at FLEXCAN_TX_BUF_ID + 1

drivers/net/can/flexcan.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 630c7bf..56eb375 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -801,6 +801,7 @@ static int flexcan_chip_start(struct net_device *dev)
struct flexcan_regs __iomem *regs = priv->base;
int err;
u32 reg_mcr, reg_ctrl;
+ int i;

/* enable module */
err = flexcan_chip_enable(priv);
@@ -867,6 +868,12 @@ 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);

+ /* Clear and invalidate all mailboxes first */
+ for (i = FLEXCAN_TX_BUF_ID; i < ARRAY_SIZE(regs->cantxfg; i++) {
+ flexcan_write(FLEXCAN_MB_CNT_CODE(0x0),
+ &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);

[Marc Kleine-Budde]

This patch increases the mask in the FLEXCAN_MCR_MAXMB() to 7 bits as in the
newer flexcan cores the MAXMB field is 7 bits wide.

Reported-by: David Jander <***@protonic.nl>
Signed-off-by: Marc Kleine-Budde <***@pengutronix.de>
---
Changes since v2:
- none

Changes since v1:
- new

drivers/net/can/flexcan.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 56eb375..32b1057 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) & 0x1f)
+#define FLEXCAN_MCR_MAXMB(x) ((x) & 0x7f)
#define FLEXCAN_MCR_IDAM_A (0 << 8)
#define FLEXCAN_MCR_IDAM_B (1 << 8)
#define FLEXCAN_MCR_IDAM_C (2 << 8)