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1bb1ff3e7c
There is a race between the TWSI interrupt and the condition that is required before proceeding: Low-level: interrupt flag bit must be set High-level controller: valid bit must be clear If the interrupt comes too early and the condition is not met the wait will time out, and the transfer is aborted leading to very poor performance. To avoid this race retry for the condition ~80 µs later. The retry is avoided on the very first invocation of wait_event_timeout() (which tests the condition before entering the wait and is therefore always wrong in this case). EEPROM reads on 100kHz i2c now measure ~5.2kB/s, about 1/2 what's achievable, and much better than the worst-case 100 bytes/sec before. While at it remove the debug print from the low-level wait function. Signed-off-by: Peter Swain <pswain@cavium.com> Signed-off-by: Jan Glauber <jglauber@cavium.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> |
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| .. | ||
| algos | ||
| busses | ||
| muxes | ||
| i2c-boardinfo.c | ||
| i2c-core.c | ||
| i2c-core.h | ||
| i2c-dev.c | ||
| i2c-mux.c | ||
| i2c-slave-eeprom.c | ||
| i2c-smbus.c | ||
| i2c-stub.c | ||
| Kconfig | ||
| Makefile | ||