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| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2009-05-08 18:29:27 -0700 |
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| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2009-05-08 18:29:27 -0700 |
| commit | d585a021c0b10b0477d6b608c53e1feb8cde0507 (patch) | |
| tree | 5ca059da1db7f15d4b29427644ad9c08270c885c /Documentation/spi/spi-summary | |
| parent | 84e5b0d00f8f84c4ae226be131d4bebbcee88bd3 (diff) | |
| parent | 091bf7624d1c90cec9e578a18529f615213ff847 (diff) | |
Merge commit 'v2.6.30-rc5' into next
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 |