From 8a0e0a49b0a917c8c8dce6f7121ec73a5c8e3932 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Thu, 21 Oct 2010 01:01:14 +0000 Subject: [PATCH] can: at91_can: fix reception of extended frames The AT91_MID_MIDE bit must be set in order to receive extended frames. The reception of an extended frame sets this bit, while reception of standard frames resets it. This results in some lost extended frames in an extended ID only environment. But leads to unpredictable lost extended ID frames in a mixed environment. The problem is fixed by setting the AT91_MID_MIDE after reception of a CAN frame. Signed-off-by: Marc Kleine-Budde Signed-off-by: David S. Miller --- drivers/net/can/at91_can.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c index b2a4599eb1d7..3b66c6736832 100644 --- a/drivers/net/can/at91_can.c +++ b/drivers/net/can/at91_can.c @@ -243,6 +243,12 @@ static void at91_setup_mailboxes(struct net_device *dev) set_mb_mode(priv, i, AT91_MB_MODE_RX); set_mb_mode(priv, AT91_MB_RX_LAST, AT91_MB_MODE_RX_OVRWR); + /* reset acceptance mask and id register */ + for (i = AT91_MB_RX_FIRST; i <= AT91_MB_RX_LAST; i++) { + at91_write(priv, AT91_MAM(i), 0x0 ); + at91_write(priv, AT91_MID(i), AT91_MID_MIDE); + } + /* The last 4 mailboxes are used for transmitting. */ for (i = AT91_MB_TX_FIRST; i <= AT91_MB_TX_LAST; i++) set_mb_mode_prio(priv, i, AT91_MB_MODE_TX, 0); @@ -480,6 +486,9 @@ static void at91_read_mb(struct net_device *dev, unsigned int mb, *(u32 *)(cf->data + 0) = at91_read(priv, AT91_MDL(mb)); *(u32 *)(cf->data + 4) = at91_read(priv, AT91_MDH(mb)); + /* allow RX of extended frames */ + at91_write(priv, AT91_MID(mb), AT91_MID_MIDE); + if (unlikely(mb == AT91_MB_RX_LAST && reg_msr & AT91_MSR_MMI)) at91_rx_overflow_err(dev); } -- 2.20.1