Re: [PATCHv5 1/2] i2c: designware: introduce a custom scl recovery for SoCFPGA platforms

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 





On 6/17/22 07:59, Jarkko Nikula wrote:
Hi

On 6/16/22 17:12, Dinh Nguyen wrote:
The I2C pins on the SoCFPGA platforms do not go through a GPIO module,
thus cannot be recovered by the default method of by doing a GPIO access.
Only a reset of the I2C IP block can a recovery be successful.

One thing what is unclear to me how does this release the I2C slave that potentially keeps the SDA stuck low. Does platform specific reset sequence send 9 SCL pulses, toggle HW reset of the clients or cycle power of them?

If recovery is only controller point of view then worth to emphasis it in the commit log and perhaps add a comment too into i2c_socfpga_scl_recovery(). Some might hit an issue that I2C client is stuck and wonder why recovery won't work.

The recovery is only resetting the controller itself and not the client. I'll add a comment in v6 to highlight this.

The assignment of the recover_bus needs to get done before the call to
devm_gpiod_get_optional(), otherwise, the assignment is not taking place
because of an error after returning from devm_gpiod_get_optional().

This sentence no longer true after v3?

Correct...will update.

Dinh



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux