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Commit 5c57a901 authored by Ido Yariv's avatar Ido Yariv Committed by Luciano Coelho
Browse files

wl1271: Handle large SPI transfers 



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: default avatarIdo Yariv <ido@wizery.com>
Tested-by: default avatarJuuso Oikarinen <juuso.oikarinen@nokia.com>
Signed-off-by: default avatarLuciano Coelho <luciano.coelho@nokia.com>
parent 65836112

drivers/net/wireless/wl12xx/wl1271_spi.c

+86 −54
Original line number Diff line number Diff line
@@ -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;
@@ -202,17 +207,22 @@ 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;



	while (len > 0) {

		chunk_len = min((size_t)WSPI_MAX_CHUNK_SIZE, len);



		cmd = &wl->buffer_cmd;

		busy_buf = wl->buffer_busyword;



		*cmd = 0;

		*cmd |= WSPI_CMD_READ;

	*cmd |= (len << WSPI_CMD_BYTE_LENGTH_OFFSET) & WSPI_CMD_BYTE_LENGTH;

		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &

			WSPI_CMD_BYTE_LENGTH;

		*cmd |= addr & WSPI_CMD_BYTE_ADDR;



		if (fixed)
@@ -236,7 +246,7 @@ static void wl1271_spi_raw_read(struct wl1271 *wl, int addr, void *buf, 


		if (!(busy_buf[WL1271_BUSY_WORD_CNT - 1] & 0x1) &&

		    wl1271_spi_read_busy(wl)) {

		memset(buf, 0, len);

			memset(buf, 0, chunk_len);

			return;

		}
@@ -244,48 +254,70 @@ static void wl1271_spi_raw_read(struct wl1271 *wl, int addr, void *buf, 
		memset(t, 0, sizeof(t));



		t[0].rx_buf = buf;

	t[0].len = len;

		t[0].len = chunk_len;

		t[0].cs_change = true;

		spi_message_add_tail(&t[0], &m);



		spi_sync(wl_to_spi(wl), &m);



		wl1271_dump(DEBUG_SPI, "spi_read cmd -> ", cmd, sizeof(*cmd));

	wl1271_dump(DEBUG_SPI, "spi_read buf <- ", buf, len);

		wl1271_dump(DEBUG_SPI, "spi_read buf <- ", buf, chunk_len);



		if (!fixed)

			addr += chunk_len;

		buf += chunk_len;

		len -= chunk_len;

	}

}



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;

	WARN_ON(len > WL1271_AGGR_BUFFER_SIZE);



	spi_message_init(&m);

	memset(t, 0, sizeof(t));



	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 |= (len << WSPI_CMD_BYTE_LENGTH_OFFSET) & WSPI_CMD_BYTE_LENGTH;

		*cmd |= (chunk_len << WSPI_CMD_BYTE_LENGTH_OFFSET) &

			WSPI_CMD_BYTE_LENGTH;

		*cmd |= addr & WSPI_CMD_BYTE_ADDR;



		if (fixed)

			*cmd |= WSPI_CMD_FIXED;



	spi_message_init(&m);

	memset(t, 0, sizeof(t));

		t[i].tx_buf = cmd;

		t[i].len = sizeof(*cmd);

		spi_message_add_tail(&t[i++], &m);



	t[0].tx_buf = cmd;

	t[0].len = sizeof(*cmd);

	spi_message_add_tail(&t[0], &m);

		t[i].tx_buf = buf;

		t[i].len = chunk_len;

		spi_message_add_tail(&t[i++], &m);



	t[1].tx_buf = buf;

	t[1].len = len;

	spi_message_add_tail(&t[1], &m);

		wl1271_dump(DEBUG_SPI, "spi_write cmd -> ", cmd, sizeof(*cmd));

		wl1271_dump(DEBUG_SPI, "spi_write buf -> ", buf, chunk_len);



	spi_sync(wl_to_spi(wl), &m);

		if (!fixed)

			addr += chunk_len;

		buf += chunk_len;

		len -= chunk_len;

		cmd++;

	}



	wl1271_dump(DEBUG_SPI, "spi_write cmd -> ", cmd, sizeof(*cmd));

	wl1271_dump(DEBUG_SPI, "spi_write buf -> ", buf, len);

	spi_sync(wl_to_spi(wl), &m);

}



static irqreturn_t wl1271_irq(int irq, void *cookie)