[PATCH 2/8] i2c: at91: add warning about transmission issues for some devices
From: ludovic.desroches at atmel.com <hidden>
Date: 2012-08-31 09:21:18
Also in:
linux-devicetree, linux-i2c
Subsystem:
i2c subsystem, i2c subsystem host drivers, the rest · Maintainers:
Wolfram Sang, Andi Shyti, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2012-09-03 · RE: [PATCH 2/8] i2c: at91: add warning about transmission issues for some devices · Voss, Nikolaus <hidden>
From: Ludovic Desroches <redacted> Some devices don't have clock streching in transmission mode. It can lead to premature stop sendings if the latency to write data in the transmission register is too long. In this case, prefer the i2c-gpio driver. Signed-off-by: Ludovic Desroches <redacted> --- drivers/i2c/busses/Kconfig | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index d9c4918..da77c37 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig@@ -300,6 +300,12 @@ config I2C_AT91 to support combined I2C messages. Use the i2c-gpio driver unless your system can cope with this limitation. + Caution! at91rm9200, at91sam9261, at91sam9260, at91sam9263 devices + don't have clock stretching in transmission mode. For that reason, + you can encounter underrun issues causing premature stop sendings if + the latency to fill the transmission register is too long. If you + are facing this situation, use the i2c-gpio driver. + config I2C_AU1550 tristate "Au1550/Au1200/Au1300 SMBus interface" depends on MIPS_ALCHEMY
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1.7.11.3