Hi Simon,
On 01.03.2017 06:40, Simon Glass wrote:
On 28 February 2017 at 09:32, Stefan Roese sr@denx.de wrote:
Hi!
I'm currently trying to add some code to stop (DMA) buffer usage in the Marvell mvpp2 ethernet driver, that should only be executed once, before the OS is started - stop() does not work easily for me here. I've found the weak function "board_quiesce_devices()", which is already used for such cases. But since you are not fond of weak functions (I totally agree here, this is far from perfect) and already suggested some kind of "finalize" DM API call, I'm wondering if I should introduce this new API call for such cases and use it in the ethernet driver.
So what is your opinion about this? Should I add such a finalize DM function and call it from the arch/.../bootm code? Or do you have other suggestions on how to handle such driver specific last-stage (pre OS) calls?
Is it possible to use the device's remove() method?
I also thought about this of course. Using remove has the following disadvantages, that I currently can think of:
- The remove functions of all devices are called, adding to the bootup time
- Since all devices are removed, serial (and other) output is not available (for debug purposes) any more
It should be possible to add a DM flag to enable this pre-OS device remove, which could be enabled on a per-device basis. This way we don't need another API function. But still I need to hook this pre-OS "remove" into arch/.../bootm.
What do you think?
Thanks, Stefan