The HW supports up to 4095 bytes transfers via SPI. The SPI read & write
operations do not handle larger transfers, causing the HW to stall in such
cases.
Fix this by fragmenting large transfers into smaller chunks, and
transferring each one separately.
Signed-off-by: Ido Yariv <ido@xxxxxxxxxx>
Tested-by: Juuso Oikarinen <juuso.oikarinen@xxxxxxxxx>
---
drivers/net/wireless/wl12xx/wl1271_spi.c | 132 ++++++++++++++++++-----------
1 files changed, 82 insertions(+), 50 deletions(-)
diff --git a/drivers/net/wireless/wl12xx/wl1271_spi.c b/drivers/net/wireless/wl12xx/wl1271_spi.c
index 75cbf36..71336ef 100644
--- a/drivers/net/wireless/wl12xx/wl1271_spi.c
+++ b/drivers/net/wireless/wl12xx/wl1271_spi.c
@@ -63,6 +63,11 @@
((WL1271_BUSY_WORD_LEN - 4) / sizeof(u32))
#define HW_ACCESS_WSPI_INIT_CMD_MASK 0
+/* HW limitation: maximum possible chunk size is 4095 bytes */
+#define WSPI_MAX_CHUNK_SIZE 4092
+
+#define WSPI_MAX_NUM_OF_CHUNKS (WL1271_AGGR_BUFFER_SIZE / WSPI_MAX_CHUNK_SIZE)
+
static inline struct spi_device *wl_to_spi(struct wl1271 *wl)
{
return wl->if_priv;
@@ -202,53 +207,64 @@ static int wl1271_spi_read_busy(struct wl1271 *wl)
static void wl1271_spi_raw_read(struct wl1271 *wl, int addr, void *buf,
size_t len, bool fixed)
{
- struct spi_transfer t[3];
+ struct spi_transfer t[2];
struct spi_message m;
u32 *busy_buf;
u32 *cmd;
+ u32 chunk_len;
- cmd = &wl->buffer_cmd;
- busy_buf = wl->buffer_busyword;
+ while (len > 0) {
+ chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);
- *cmd = 0;
- *cmd |= WSPI_CMD_READ;
- *cmd |= (len << WSPI_CMD_BYTE_LENGTH_OFFSET) & WSPI_CMD_BYTE_LENGTH;
- *cmd |= addr & WSPI_CMD_BYTE_ADDR;
+ cmd = &wl->buffer_cmd;
+ busy_buf = wl->buffer_busyword;
- if (fixed)
- *cmd |= WSPI_CMD_FIXED;
+ *cmd = 0;
+ *cmd |= WSPI_CMD_READ;
+ *cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
+ WSPI_CMD_BYTE_LENGTH;
+ *cmd |= addr & WSPI_CMD_BYTE_ADDR;
- spi_message_init(&m);
- memset(t, 0, sizeof(t));
+ if (fixed)
+ *cmd |= WSPI_CMD_FIXED;
- t[0].tx_buf = cmd;
- t[0].len = 4;
- t[0].cs_change = true;
- spi_message_add_tail(&t[0], &m);
+ spi_message_init(&m);
+ memset(t, 0, sizeof(t));
- /* Busy and non busy words read */
- t[1].rx_buf = busy_buf;
- t[1].len = WL1271_BUSY_WORD_LEN;
- t[1].cs_change = true;
- spi_message_add_tail(&t[1], &m);
+ t[0].tx_buf = cmd;
+ t[0].len = 4;
+ t[0].cs_change = true;
+ spi_message_add_tail(&t[0], &m);
- spi_sync(wl_to_spi(wl), &m);
+ /* Busy and non busy words read */
+ t[1].rx_buf = busy_buf;
+ t[1].len = WL1271_BUSY_WORD_LEN;
+ t[1].cs_change = true;
+ spi_message_add_tail(&t[1], &m);
- if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
- wl1271_spi_read_busy(wl)) {
- memset(buf, 0, len);
- return;
- }
+ spi_sync(wl_to_spi(wl), &m);
- spi_message_init(&m);
- memset(t, 0, sizeof(t));
+ if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&
+ wl1271_spi_read_busy(wl)) {
+ memset(buf, 0, chunk_len);
+ return;
+ }
- t[0].rx_buf = buf;
- t[0].len = len;
- t[0].cs_change = true;
- spi_message_add_tail(&t[0], &m);
+ spi_message_init(&m);
+ memset(t, 0, sizeof(t));
- spi_sync(wl_to_spi(wl), &m);
+ t[0].rx_buf = buf;
+ t[0].len = chunk_len;
+ t[0].cs_change = true;
+ spi_message_add_tail(&t[0], &m);
+
+ spi_sync(wl_to_spi(wl), &m);
+
+ if (!fixed)
+ addr += chunk_len;
+ buf += chunk_len;
+ len -= chunk_len;
+ }
wl1271_dump(DEBUG_SPI, "spi_read cmd -> ", cmd, sizeof(*cmd));
wl1271_dump(DEBUG_SPI, "spi_read buf <- ", buf, len);
@@ -257,30 +273,46 @@ static void wl1271_spi_raw_read(struct wl1271 *wl, int addr, void *buf,
static void wl1271_spi_raw_write(struct wl1271 *wl, int addr, void *buf,
size_t len, bool fixed)
{
- struct spi_transfer t[2];
+ struct spi_transfer t[2 * WSPI_MAX_NUM_OF_CHUNKS];
struct spi_message m;
+ u32 commands[WSPI_MAX_NUM_OF_CHUNKS];
u32 *cmd;
+ u32 chunk_len;
+ int i;
- cmd = &wl->buffer_cmd;
-
- *cmd = 0;
- *cmd |= WSPI_CMD_WRITE;
- *cmd |= (len << WSPI_CMD_BYTE_LENGTH_OFFSET) & WSPI_CMD_BYTE_LENGTH;
- *cmd |= addr & WSPI_CMD_BYTE_ADDR;
-
- if (fixed)
- *cmd |= WSPI_CMD_FIXED;
+ WARN_ON(len > WL1271_AGGR_BUFFER_SIZE);
spi_message_init(&m);
memset(t, 0, sizeof(t));
- t[0].tx_buf = cmd;
- t[0].len = sizeof(*cmd);
- spi_message_add_tail(&t[0], &m);
-
- t[1].tx_buf = buf;
- t[1].len = len;
- spi_message_add_tail(&t[1], &m);
+ cmd = &commands[0];
+ i = 0;
+ while (len > 0) {
+ chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);
+
+ *cmd = 0;
+ *cmd |= WSPI_CMD_WRITE;
+ *cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &
+ WSPI_CMD_BYTE_LENGTH;
+ *cmd |= addr & WSPI_CMD_BYTE_ADDR;
+
+ if (fixed)
+ *cmd |= WSPI_CMD_FIXED;
+
+ t[i].tx_buf = cmd;
+ t[i].len = sizeof(*cmd);
+ spi_message_add_tail(&t[i++], &m);
+
+ t[i].tx_buf = buf;
+ t[i].len = chunk_len;
+ spi_message_add_tail(&t[i++], &m);
+
+ if (!fixed)
+ addr += chunk_len;
+ buf += chunk_len;
+ len -= chunk_len;
+ cmd++;
+ }
spi_sync(wl_to_spi(wl), &m);
--
1.7.0.4
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