Re: [PATCH v2] qmi_wwan: allow max_mtu above hard_mtu to control rx_urb_size

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@xxxxxxxxxx>:

On Wed,  4 Mar 2026 14:43:38 +0100 you wrote:
> Commit c7159e960f14 ("usbnet: limit max_mtu based on device's hard_mtu")
> capped net->max_mtu to the device's hard_mtu in usbnet_probe(). While
> this correctly prevents oversized packets on standard USB network
> devices, it breaks the qmi_wwan driver.
> 
> qmi_wwan relies on userspace (e.g. ModemManager) setting a large MTU on
> the wwan0 interface to configure rx_urb_size via usbnet_change_mtu().
> QMI modems negotiate USB transfer sizes of 16,383 or 32,767 bytes, and
> the USB receive buffers must be sized accordingly. With max_mtu capped
> to hard_mtu (~1500 bytes), userspace can no longer raise the MTU, the
> receive buffers remain small, and download speeds drop from >300 Mbps
> to ~0.8 Mbps.
> 
> [...]

Here is the summary with links:
  - [v2] qmi_wwan: allow max_mtu above hard_mtu to control rx_urb_size
    https://git.kernel.org/netdev/net/c/55f854dd5bdd

You are awesome, thank you!
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