-----Original Message-----
From: Köry Maincent <kory.maincent@bootlin.com>
Sent: Wednesday, February 7, 2024 1:29 PM
To: Elad Nachman <enachman@marvell.com>
Cc: netdev@vger.kernel.org; Taras Chornyi <redacted>;
Thomas Petazzoni [off-list ref]; Miquel Raynal
[off-list ref]
Subject: Re: [EXT] Prestera driver fail to probe twice

On Wed, 7 Feb 2024 10:56:29 +0000
Elad Nachman [off-list ref] wrote:

quoted

quoted

-----Original Message-----
From: Köry Maincent <kory.maincent@bootlin.com>
Sent: Wednesday, February 7, 2024 12:23 PM
To: Elad Nachman <enachman@marvell.com>
Cc: netdev@vger.kernel.org; Taras Chornyi
[off-list ref]; Thomas Petazzoni
[off-list ref]; Miquel Raynal
[off-list ref]
Subject: Re: [EXT] Prestera driver fail to probe twice

On Tue, 6 Feb 2024 18:30:33 +0000
Elad Nachman [off-list ref] wrote:

quoted

Sorry, that's not how this works.

The firmware CPU loader will only reload if the firmware crashed or exit.

Hence, insmod on the host side will fail, as the firmware side
loader is not waiting For the host to send a new firmware, but
first for the existing firmware to exit.

With the current implementation we can't rmmod/insmod the driver.
Also, in case of deferring probe the same problem appears and the
driver will never probe. I don't think this is a good behavior.

Isn't it possible to verify that the firmware has already been sent
and is working well at the probe time? Then we wouldn't try to flash it.

Everything is possible, but that is the way the firmware interface was
initially designed. Changing this will break compatibility with board
already deployed in the field.

I don't understand, why fixing the probe by not flashing the firmware if it is
already flashed, will break compatibility?
Do I miss something?

First, firmware is loaded to RAM and not flashed.
Second, there is a certain control loop which dictates when the firmware loader expects new firmware by ABI, and that can only happen when the previous firmware code has terminated.

Regards,
--
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
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