Skip to content

Commit

Permalink
---
Browse files Browse the repository at this point in the history
yaml
---
r: 143204
b: refs/heads/master
c: bdff549
h: refs/heads/master
v: v3
  • Loading branch information
David Brownell authored and Linus Torvalds committed Apr 13, 2009
1 parent 301423c commit 9bfefc7
Show file tree
Hide file tree
Showing 2 changed files with 15 additions and 9 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 0769c2981495c3d05429840d6fc7a1b5e26accaa
refs/heads/master: bdff549ebeff92b1a6952e5501caf16a6f8898c8
22 changes: 14 additions & 8 deletions trunk/drivers/spi/spi.c
Original file line number Diff line number Diff line change
Expand Up @@ -658,7 +658,7 @@ int spi_write_then_read(struct spi_device *spi,

int status;
struct spi_message message;
struct spi_transfer x;
struct spi_transfer x[2];
u8 *local_buf;

/* Use preallocated DMA-safe buffer. We can't avoid copying here,
Expand All @@ -669,9 +669,15 @@ int spi_write_then_read(struct spi_device *spi,
return -EINVAL;

spi_message_init(&message);
memset(&x, 0, sizeof x);
x.len = n_tx + n_rx;
spi_message_add_tail(&x, &message);
memset(x, 0, sizeof x);
if (n_tx) {
x[0].len = n_tx;
spi_message_add_tail(&x[0], &message);
}
if (n_rx) {
x[1].len = n_rx;
spi_message_add_tail(&x[1], &message);
}

/* ... unless someone else is using the pre-allocated buffer */
if (!mutex_trylock(&lock)) {
Expand All @@ -682,15 +688,15 @@ int spi_write_then_read(struct spi_device *spi,
local_buf = buf;

memcpy(local_buf, txbuf, n_tx);
x.tx_buf = local_buf;
x.rx_buf = local_buf;
x[0].tx_buf = local_buf;
x[1].rx_buf = local_buf + n_tx;

/* do the i/o */
status = spi_sync(spi, &message);
if (status == 0)
memcpy(rxbuf, x.rx_buf + n_tx, n_rx);
memcpy(rxbuf, x[1].rx_buf, n_rx);

if (x.tx_buf == buf)
if (x[0].tx_buf == buf)
mutex_unlock(&lock);
else
kfree(local_buf);
Expand Down

0 comments on commit 9bfefc7

Please sign in to comment.