On 01/09/2014 11:44 PM, Dmitry Torokhov wrote:
Instead of using 2 separate transactions when reading from the device let's
use i2c_transfer. Because we now have single point of failure I had to
change how we collect statistics. I elected to drop control data from the
stats and only track number of bytes read/written for the device data.
Also, since we are not prepared to deal with short reads and writes change
read_block_data and write_block_data to indicate error if we detect short
transfers.
Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com>
---
drivers/input/rmi4/rmi_i2c.c | 71 ++++++++++++++++++++++++--------------------
1 file changed, 39 insertions(+), 32 deletions(-)
diff --git a/drivers/input/rmi4/rmi_i2c.c b/drivers/input/rmi4/rmi_i2c.c
index c176218..51f5bc8 100644
--- a/drivers/input/rmi4/rmi_i2c.c
+++ b/drivers/input/rmi4/rmi_i2c.c
@@ -57,22 +57,17 @@ struct rmi_i2c_xport {
*/
static int rmi_set_page(struct rmi_i2c_xport *rmi_i2c, u8 page)
{
- struct rmi_transport_dev *xport = &rmi_i2c->xport;
struct i2c_client *client = rmi_i2c->client;
u8 txbuf[2] = {RMI_PAGE_SELECT_REGISTER, page};
int retval;
- dev_dbg(&client->dev, "writes 3 bytes: %02x %02x\n",
- txbuf[0], txbuf[1]);
- xport->stats.tx_count++;
- xport->stats.tx_bytes += sizeof(txbuf);
retval = i2c_master_send(client, txbuf, sizeof(txbuf));
if (retval != sizeof(txbuf)) {
- xport->stats.tx_errs++;
dev_err(&client->dev,
"%s: set page failed: %d.", __func__, retval);
return (retval < 0) ? retval : -EIO;
}
+
rmi_i2c->page = page;
return 0;
}
@@ -107,22 +102,27 @@ static int rmi_i2c_write_block(struct rmi_transport_dev
*xport, u16 addr,
if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
- if (retval < 0)
+ if (retval)
goto exit;
}
+ retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size);
+ if (retval == tx_size)
+ retval = 0;
+ else if (retval >= 0)
+ retval = -EIO;
+
+exit:
dev_dbg(&client->dev,
- "writes %zd bytes at %#06x: %*ph\n", len, addr, (int)len, buf);
+ "write %zd bytes at %#06x: %d (%*ph)\n",
+ len, addr, retval, (int)len, buf);
xport->stats.tx_count++;
- xport->stats.tx_bytes += tx_size;
- retval = i2c_master_send(client, rmi_i2c->tx_buf, tx_size);
- if (retval < 0)
+ if (retval)
xport->stats.tx_errs++;
else
- retval--; /* don't count the address byte */
+ xport->stats.tx_bytes += len;
-exit:
mutex_unlock(&rmi_i2c->page_mutex);
return retval;
}
@@ -133,40 +133,47 @@ static int rmi_i2c_read_block(struct rmi_transport_dev
*xport, u16 addr,
struct rmi_i2c_xport *rmi_i2c =
container_of(xport, struct rmi_i2c_xport, xport);
struct i2c_client *client = rmi_i2c->client;
- u8 txbuf[1] = {addr & 0xff};
+ u8 addr_offset = addr & 0xff;
int retval;
+ struct i2c_msg msgs[] = {
+ {
+ .addr = client->addr,
+ .len = sizeof(addr_offset),
+ .buf = &addr_offset,
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = len,
+ .buf = buf,
+ },
+ };
mutex_lock(&rmi_i2c->page_mutex);
if (RMI_I2C_PAGE(addr) != rmi_i2c->page) {
retval = rmi_set_page(rmi_i2c, RMI_I2C_PAGE(addr));
- if (retval < 0)
+ if (retval)
goto exit;
}
- dev_dbg(&client->dev, "writes 1 bytes: %02x\n", txbuf[0]);
+ retval = i2c_transfer(client->adapter, msgs, sizeof(msgs));
+ if (retval == sizeof(msgs))
I think this should be:
retval = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
if (retval == ARRAY_SIZE(msgs))
At least, that change resolved some random misbehaviors, including
kernel panics.
+ retval = 0; /* success */
+ else if (retval >= 0)
+ retval = -EIO;
- xport->stats.tx_count++;
- xport->stats.tx_bytes += sizeof(txbuf);
- retval = i2c_master_send(client, txbuf, sizeof(txbuf));
- if (retval != sizeof(txbuf)) {
- xport->stats.tx_errs++;
- retval = (retval < 0) ? retval : -EIO;
- goto exit;
- }
+exit:
+ dev_dbg(&client->dev,
+ "read %zd bytes at %#06x: %d (%*ph)\n",
+ len, addr, retval, (int)len, buf);
xport->stats.rx_count++;
- xport->stats.rx_bytes += len;
-
- retval = i2c_master_recv(client, buf, len);
- if (retval < 0)
+ if (retval)
xport->stats.rx_errs++;
else
- dev_dbg(&client->dev,
- "read %zd bytes at %#06x: %*ph\n",
- len, addr, (int)len, buf);
+ xport->stats.rx_bytes += len;
-exit:
mutex_unlock(&rmi_i2c->page_mutex);
return retval;
}
--
Christopher Heiny
Senior Staff Firmware Engineer
Synaptics Incorporated
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
