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| author | Ingo Molnar <mingo@elte.hu> | 2009-05-11 14:44:27 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-05-11 14:44:31 +0200 |
| commit | 41fb454ebe6024f5c1e3b3cbc0abc0da762e7b51 (patch) | |
| tree | 51c50bcb67a5039448ddfa1869d7948cab1217e9 /Documentation/spi/spi-summary | |
| parent | 19c1a6f5764d787113fa323ffb18be7991208f82 (diff) | |
| parent | 091bf7624d1c90cec9e578a18529f615213ff847 (diff) | |
Merge commit 'v2.6.30-rc5' into core/iommu
Merge reason: core/iommu was on an .30-rc1 base,
update it to .30-rc5 to refresh.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
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 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 |