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| author | David S. Miller <davem@davemloft.net> | 2009-05-18 21:08:20 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-05-18 21:08:20 -0700 |
| commit | bb803cfbecb03a0cf8dc7e1864f18dda6631af00 (patch) | |
| tree | 6c0989693bea6f50cfa5c6bb14f52ec19668def3 /Documentation/spi/spi-summary | |
| parent | 3878fb6fdbceecca20b15748f807340854220f06 (diff) | |
| parent | 511e11e396dc596825ce04d53d7f6d579404bc01 (diff) | |
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-summary | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary index 0f5122eb282..4a02d2508bc 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 |