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| author | Gavin Shan <gwshan@linux.vnet.ibm.com> | 2015-11-12 13:33:09 +1100 |
|---|---|---|
| committer | Stewart Smith <stewart@linux.vnet.ibm.com> | 2016-03-08 18:18:51 +1100 |
| commit | 2c3c14a14b13d9a180cb22896d878ffa96c39f1e (patch) | |
| tree | 76b002916a9a42efc12375f96ad1a3af5d57d500 /hw/p8-i2c.c | |
| parent | 5cda6f6de5af22b7602901584b6eeca099e50b20 (diff) | |
| download | skiboot-2c3c14a14b13d9a180cb22896d878ffa96c39f1e.zip skiboot-2c3c14a14b13d9a180cb22896d878ffa96c39f1e.tar.gz skiboot-2c3c14a14b13d9a180cb22896d878ffa96c39f1e.tar.bz2 | |
hw/p8-i2c: Speed up SMBUS_WRITE
For SMBUS_WRITE, the register offset and the following data can be
sent to I2C bus in one shoot if the FIFO has enough spare space.
It helps to gain a bit more performance obviously.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
Diffstat (limited to 'hw/p8-i2c.c')
| -rw-r--r-- | hw/p8-i2c.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/hw/p8-i2c.c b/hw/p8-i2c.c index 5dd407d..7ca5f70 100644 --- a/hw/p8-i2c.c +++ b/hw/p8-i2c.c @@ -589,10 +589,15 @@ static void p8_i2c_status_data_request(struct p8_i2c_master *master, rc = p8_i2c_fifo_write(master, master->obuf, req->offset_bytes); } + + /* For read, wait address phase to complete */ + if (rc || req->op != SMBUS_WRITE) + break; + /* For writes, transition to data phase now */ - if (rc == 0 && req->op == SMBUS_WRITE) - master->state = state_data; - break; + master->state = state_data; + fifo_free -= req->offset_bytes; + /* Fall through */ case state_data: /* Sanity check */ if (master->bytes_sent >= req->rw_len) { |