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Date: Thu, 25 Jan 2024 22:03:37 +0100
From: Andrew Lunn <andrew@lunn.ch>
To: Danielle Ratson <danieller@nvidia.com>
Cc: netdev@vger.kernel.org, davem@davemloft.net, edumazet@google.com,
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Subject: Re: [RFC PATCH net-next 9/9] ethtool: Add ability to flash
 transceiver modules' firmware
Message-ID: <5bf6b526-02c4-4940-b8ec-bf858f9d4a58@lunn.ch>
References: <20240122084530.32451-1-danieller@nvidia.com>
 <20240122084530.32451-10-danieller@nvidia.com>
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In-Reply-To: <20240122084530.32451-10-danieller@nvidia.com>

> +static int
> +module_flash_fw_schedule(struct net_device *dev,
> +			 struct ethtool_module_fw_flash_params *params,
> +			 struct netlink_ext_ack *extack)
> +{
> +	const struct ethtool_ops *ops = dev->ethtool_ops;
> +	struct ethtool_module_fw_flash *module_fw;
> +	int err;
> +
> +	if (!ops->set_module_eeprom_by_page ||
> +	    !ops->get_module_eeprom_by_page) {
> +		NL_SET_ERR_MSG(extack,
> +			       "Flashing module firmware is not supported by this device");
> +		return -EOPNOTSUPP;
> +	}
> +
> +	if (dev->module_fw_flash_in_progress) {
> +		NL_SET_ERR_MSG(extack, "Module firmware flashing already in progress");
> +		return -EBUSY;
> +	}
> +
> +	module_fw = kzalloc(sizeof(*module_fw), GFP_KERNEL);
> +	if (!module_fw)
> +		return -ENOMEM;
> +
> +	module_fw->params = *params;
> +	err = request_firmware(&module_fw->fw, module_fw->params.file_name,
> +			       &dev->dev);

How big are these firmware blobs?

Ideally we want to be able to use the same API to upgrade things like
GPON modules, which often run an openwrt image, and they are plugged
into a cable modem which does not have too much RAM.

Given that the interface to the EEPROM is using 128 byte 1/2 pages,
would it be possible to use request_partial_firmware_into_buf() to
read it on demand, rather than all at once?

     Andrew