summaryrefslogtreecommitdiffstats
path: root/Documentation/spi/spi-summary
diff options
context:
space:
mode:
authorDavid S. Miller <davem@davemloft.net>2009-05-18 21:08:20 -0700
committerDavid S. Miller <davem@davemloft.net>2009-05-18 21:08:20 -0700
commitbb803cfbecb03a0cf8dc7e1864f18dda6631af00 (patch)
tree6c0989693bea6f50cfa5c6bb14f52ec19668def3 /Documentation/spi/spi-summary
parent3878fb6fdbceecca20b15748f807340854220f06 (diff)
parent511e11e396dc596825ce04d53d7f6d579404bc01 (diff)
downloadtalos-op-linux-bb803cfbecb03a0cf8dc7e1864f18dda6631af00.tar.gz
talos-op-linux-bb803cfbecb03a0cf8dc7e1864f18dda6631af00.zip
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts: drivers/scsi/fcoe/fcoe.c
Diffstat (limited to 'Documentation/spi/spi-summary')
-rw-r--r--Documentation/spi/spi-summary6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary
index 0f5122eb282b..4a02d2508bc8 100644
--- a/Documentation/spi/spi-summary
+++ b/Documentation/spi/spi-summary
@@ -511,10 +511,16 @@ SPI MASTER METHODS
This sets up the device clock rate, SPI mode, and word sizes.
Drivers may change the defaults provided by board_info, and then
call spi_setup(spi) to invoke this routine. It may sleep.
+
Unless each SPI slave has its own configuration registers, don't
change them right away ... otherwise drivers could corrupt I/O
that's in progress for other SPI devices.
+ ** BUG ALERT: for some reason the first version of
+ ** many spi_master drivers seems to get this wrong.
+ ** When you code setup(), ASSUME that the controller
+ ** is actively processing transfers for another device.
+
master->transfer(struct spi_device *spi, struct spi_message *message)
This must not sleep. Its responsibility is arrange that the
transfer happens and its complete() callback is issued. The two
OpenPOWER on IntegriCloud