On 29.03.18 06:02, Joe Hershberger wrote:
Hi Patrick,
On Wed, Mar 28, 2018 at 4:54 PM, Fabio Estevam festevam@gmail.com wrote:
Adding Joe in case he has some ideas.
On Tue, Mar 27, 2018 at 9:12 AM, Patrick Wildt patrick@blueri.se wrote:
Hi,
I have been debugging network issues when running an EFI Application that uses the EFI Simple Network protocol on an i.MX6 machine (FEC).
The symptom is that u-boot's (FEC) internal RX ring index is reset to 0, while the controller is still at idx 3 (or something else). This is caused by the following circumstances:
The Simple Network protocol offers methods like Start(), Stop(), Initialize(), Shutdown(), Reset(). Also the protocol has a state. The states are Stopped, Started, Initialized. The transition is as follows:
Stopped ---Start()---> Started ---Initialize()--> Initialized
Start() does some initialization, Initialize() allocates the TX/RX descriptors and actually kicks off the network engine.
So far, only Initialize() is implemented in our u-boot interface, and it calls eth_init() which in the end calls fec_init(). Our network state is _always_ Started. This means that EFI Applications see that that the state is Started and then call Initialize() to start the actual network traffic. There is no call to Stop()/Shutdown()/Reset() as it's supposed to be in a sane state.
In my case the FEC is already initialized since I booted using network and the RX desc index is already non-zero. Now the EFI Application sees that the state is Started, calls Initialize() which makes u-boot call eth_init() which then calls fec_init().
fec_init() does not reset the controller so that the controller-internal RX desc index is not reset to zero. fec_init() calls fec_open() which then resets the driver-internal RX desc index to zero. Now they are out of sync, boom.
Would it be reasonable for fec_init to use a state variable to keep track of if it (and the HW) is already initialized and not call fec_open in that case? Also, fec_halt would need to update that state as well.
Ping? Is this still an issue?
Alex