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-rw-r--r--drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c2
-rw-r--r--drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c125
-rw-r--r--drivers/net/can/spi/mcp251xfd/mcp251xfd.h13
3 files changed, 70 insertions, 70 deletions
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
index bfe4caa0c9..4cb79a4f24 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c
@@ -485,6 +485,8 @@ int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
clear_bit(MCP251XFD_FLAGS_FD_MODE, priv->flags);
}
+ tx_ring->obj_num_shift_to_u8 = BITS_PER_TYPE(tx_ring->obj_num) -
+ ilog2(tx_ring->obj_num);
tx_ring->obj_size = tx_obj_size;
rem = priv->rx_obj_num;
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c
index e5bd57b65a..5b0c7890d4 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-tef.c
@@ -2,7 +2,7 @@
//
// mcp251xfd - Microchip MCP251xFD Family CAN controller driver
//
-// Copyright (c) 2019, 2020, 2021 Pengutronix,
+// Copyright (c) 2019, 2020, 2021, 2023 Pengutronix,
// Marc Kleine-Budde <kernel@pengutronix.de>
//
// Based on:
@@ -16,6 +16,11 @@
#include "mcp251xfd.h"
+static inline bool mcp251xfd_tx_fifo_sta_full(u32 fifo_sta)
+{
+ return !(fifo_sta & MCP251XFD_REG_FIFOSTA_TFNRFNIF);
+}
+
static inline int
mcp251xfd_tef_tail_get_from_chip(const struct mcp251xfd_priv *priv,
u8 *tef_tail)
@@ -56,55 +61,38 @@ static int mcp251xfd_check_tef_tail(const struct mcp251xfd_priv *priv)
}
static int
-mcp251xfd_handle_tefif_recover(const struct mcp251xfd_priv *priv, const u32 seq)
-{
- const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
- u32 tef_sta;
- int err;
-
- err = regmap_read(priv->map_reg, MCP251XFD_REG_TEFSTA, &tef_sta);
- if (err)
- return err;
-
- if (tef_sta & MCP251XFD_REG_TEFSTA_TEFOVIF) {
- netdev_err(priv->ndev,
- "Transmit Event FIFO buffer overflow.\n");
- return -ENOBUFS;
- }
-
- netdev_info(priv->ndev,
- "Transmit Event FIFO buffer %s. (seq=0x%08x, tef_tail=0x%08x, tef_head=0x%08x, tx_head=0x%08x).\n",
- tef_sta & MCP251XFD_REG_TEFSTA_TEFFIF ?
- "full" : tef_sta & MCP251XFD_REG_TEFSTA_TEFNEIF ?
- "not empty" : "empty",
- seq, priv->tef->tail, priv->tef->head, tx_ring->head);
-
- /* The Sequence Number in the TEF doesn't match our tef_tail. */
- return -EAGAIN;
-}
-
-static int
mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
const struct mcp251xfd_hw_tef_obj *hw_tef_obj,
unsigned int *frame_len_ptr)
{
struct net_device_stats *stats = &priv->ndev->stats;
+ u32 seq, tef_tail_masked, tef_tail;
struct sk_buff *skb;
- u32 seq, seq_masked, tef_tail_masked, tef_tail;
- seq = FIELD_GET(MCP251XFD_OBJ_FLAGS_SEQ_MCP2518FD_MASK,
+ /* Use the MCP2517FD mask on the MCP2518FD, too. We only
+ * compare 7 bits, this is enough to detect old TEF objects.
+ */
+ seq = FIELD_GET(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK,
hw_tef_obj->flags);
-
- /* Use the MCP2517FD mask on the MCP2518FD, too. We only
- * compare 7 bits, this should be enough to detect
- * net-yet-completed, i.e. old TEF objects.
- */
- seq_masked = seq &
- field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
tef_tail_masked = priv->tef->tail &
field_mask(MCP251XFD_OBJ_FLAGS_SEQ_MCP2517FD_MASK);
- if (seq_masked != tef_tail_masked)
- return mcp251xfd_handle_tefif_recover(priv, seq);
+
+ /* According to mcp2518fd erratum DS80000789E 6. the FIFOCI
+ * bits of a FIFOSTA register, here the TX FIFO tail index
+ * might be corrupted and we might process past the TEF FIFO's
+ * head into old CAN frames.
+ *
+ * Compare the sequence number of the currently processed CAN
+ * frame with the expected sequence number. Abort with
+ * -EBADMSG if an old CAN frame is detected.
+ */
+ if (seq != tef_tail_masked) {
+ netdev_dbg(priv->ndev, "%s: chip=0x%02x ring=0x%02x\n", __func__,
+ seq, tef_tail_masked);
+ stats->tx_fifo_errors++;
+
+ return -EBADMSG;
+ }
tef_tail = mcp251xfd_get_tef_tail(priv);
skb = priv->can.echo_skb[tef_tail];
@@ -120,28 +108,44 @@ mcp251xfd_handle_tefif_one(struct mcp251xfd_priv *priv,
return 0;
}
-static int mcp251xfd_tef_ring_update(struct mcp251xfd_priv *priv)
+static int
+mcp251xfd_get_tef_len(struct mcp251xfd_priv *priv, u8 *len_p)
{
const struct mcp251xfd_tx_ring *tx_ring = priv->tx;
- unsigned int new_head;
- u8 chip_tx_tail;
+ const u8 shift = tx_ring->obj_num_shift_to_u8;
+ u8 chip_tx_tail, tail, len;
+ u32 fifo_sta;
int err;
- err = mcp251xfd_tx_tail_get_from_chip(priv, &chip_tx_tail);
+ err = regmap_read(priv->map_reg, MCP251XFD_REG_FIFOSTA(priv->tx->fifo_nr),
+ &fifo_sta);
if (err)
return err;
- /* chip_tx_tail, is the next TX-Object send by the HW.
- * The new TEF head must be >= the old head, ...
+ if (mcp251xfd_tx_fifo_sta_full(fifo_sta)) {
+ *len_p = tx_ring->obj_num;
+ return 0;
+ }
+
+ chip_tx_tail = FIELD_GET(MCP251XFD_REG_FIFOSTA_FIFOCI_MASK, fifo_sta);
+
+ err = mcp251xfd_check_tef_tail(priv);
+ if (err)
+ return err;
+ tail = mcp251xfd_get_tef_tail(priv);
+
+ /* First shift to full u8. The subtraction works on signed
+ * values, that keeps the difference steady around the u8
+ * overflow. The right shift acts on len, which is an u8.
*/
- new_head = round_down(priv->tef->head, tx_ring->obj_num) + chip_tx_tail;
- if (new_head <= priv->tef->head)
- new_head += tx_ring->obj_num;
+ BUILD_BUG_ON(sizeof(tx_ring->obj_num) != sizeof(chip_tx_tail));
+ BUILD_BUG_ON(sizeof(tx_ring->obj_num) != sizeof(tail));
+ BUILD_BUG_ON(sizeof(tx_ring->obj_num) != sizeof(len));
- /* ... but it cannot exceed the TX head. */
- priv->tef->head = min(new_head, tx_ring->head);
+ len = (chip_tx_tail << shift) - (tail << shift);
+ *len_p = len >> shift;
- return mcp251xfd_check_tef_tail(priv);
+ return 0;
}
static inline int
@@ -182,13 +186,12 @@ int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
u8 tef_tail, len, l;
int err, i;
- err = mcp251xfd_tef_ring_update(priv);
+ err = mcp251xfd_get_tef_len(priv, &len);
if (err)
return err;
tef_tail = mcp251xfd_get_tef_tail(priv);
- len = mcp251xfd_get_tef_len(priv);
- l = mcp251xfd_get_tef_linear_len(priv);
+ l = mcp251xfd_get_tef_linear_len(priv, len);
err = mcp251xfd_tef_obj_read(priv, hw_tef_obj, tef_tail, l);
if (err)
return err;
@@ -203,12 +206,12 @@ int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
unsigned int frame_len = 0;
err = mcp251xfd_handle_tefif_one(priv, &hw_tef_obj[i], &frame_len);
- /* -EAGAIN means the Sequence Number in the TEF
- * doesn't match our tef_tail. This can happen if we
- * read the TEF objects too early. Leave loop let the
- * interrupt handler call us again.
+ /* -EBADMSG means we're affected by mcp2518fd erratum
+ * DS80000789E 6., i.e. the Sequence Number in the TEF
+ * doesn't match our tef_tail. Don't process any
+ * further and mark processed frames as good.
*/
- if (err == -EAGAIN)
+ if (err == -EBADMSG)
goto out_netif_wake_queue;
if (err)
return err;
@@ -223,6 +226,8 @@ int mcp251xfd_handle_tefif(struct mcp251xfd_priv *priv)
struct mcp251xfd_tx_ring *tx_ring = priv->tx;
int offset;
+ ring->head += len;
+
/* Increment the TEF FIFO tail pointer 'len' times in
* a single SPI message.
*
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
index b35bfebd23..4628bf847b 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
@@ -524,6 +524,7 @@ struct mcp251xfd_tef_ring {
/* u8 obj_num equals tx_ring->obj_num */
/* u8 obj_size equals sizeof(struct mcp251xfd_hw_tef_obj) */
+ /* u8 obj_num_shift_to_u8 equals tx_ring->obj_num_shift_to_u8 */
union mcp251xfd_write_reg_buf irq_enable_buf;
struct spi_transfer irq_enable_xfer;
@@ -542,6 +543,7 @@ struct mcp251xfd_tx_ring {
u8 nr;
u8 fifo_nr;
u8 obj_num;
+ u8 obj_num_shift_to_u8;
u8 obj_size;
struct mcp251xfd_tx_obj obj[MCP251XFD_TX_OBJ_NUM_MAX];
@@ -861,17 +863,8 @@ static inline u8 mcp251xfd_get_tef_tail(const struct mcp251xfd_priv *priv)
return priv->tef->tail & (priv->tx->obj_num - 1);
}
-static inline u8 mcp251xfd_get_tef_len(const struct mcp251xfd_priv *priv)
+static inline u8 mcp251xfd_get_tef_linear_len(const struct mcp251xfd_priv *priv, u8 len)
{
- return priv->tef->head - priv->tef->tail;
-}
-
-static inline u8 mcp251xfd_get_tef_linear_len(const struct mcp251xfd_priv *priv)
-{
- u8 len;
-
- len = mcp251xfd_get_tef_len(priv);
-
return min_t(u8, len, priv->tx->obj_num - mcp251xfd_get_tef_tail(priv));
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 21:47:23 +0000