Hi all, On Wed, Jul 14, 2021 at 10:38:31AM +0700, Quan Nguyen wrote: > Slave needs time to prepare the response data before Master could > enquiry via read transaction. However, there is no mechanism for > i2c-aspeed Slave to notify Master that it needs more time to process > and this make Master side to time out when trying to get the response. > > This commit introduces the slave_enable() callback in struct > i2c_algorithm for Slave to temporary stop the Slave mode while working > on the response and re-enable the Slave when response data ready. Sorry that I couldn't chime in earlier, but NAK! > include/linux/i2c.h | 2 ++ @Corey: Please do not change this file without my ACK. It is not a trivial change but an API extenstion and that should really be acked by the subsystem maintainer, in this case me. I was really surprised to see this in linux-next already. @all: Plus, I neither like the API (because it doesn't look generic to me but mostly handling one issue needed here) nor do I fully understand the use case. Normally, when a read is requested and the backend needs time to deliver the data, the hardware should stretch the SCL clock until some data register is finally written to. If it doesn't do it for whatever reason, this is a quirky hardware in my book and needs handling in the driver only. So, what is special with this HW? Can't we solve it differently? All the best, Wolfram
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