Re: [PATCH v3 00/17] NVMe PCI endpoint target driver

[Damien Le Moal <dlemoal@kernel.org>]

On 12/12/24 19:16, Rick Wertenbroek wrote:
> Hello,
> I have tested the NVMe endpoint function extensively on two extra
> platforms to run on, the FriendlyElec CM3588+NAS Kit [1] and NanoPC T6
> [2] (with PCIe x1, x2, and x4 links).
> 
> Besides testing with Linux based hosts (Ubuntu 20.04, 23.10, 24.04), I
> also tested that the NVMe device is recognized by a Windows 10
> Enterprise host and can be formatted and used as a regular disk. I
> also tested on MacOS Monterey on a Macbook Pro 2016 (Intel based) host
> through a M.2 to USB-C adapter [3], the drive is recognized and
> usable.
> 
> The USB-C adapter is based on the ASM2464PD chipset [4] which does
> USB4/Thunderbolt to PCIe/NVMe, I tested with PCI over Thunderbolt with
> the MacOS host, so the host sees the NVMe endpoint function directly
> as a PCI device and the NVMe drive is seen as such. This works well.
> 
> The only test case that did not work is when I tested the ASM2464PD
> chipset NVMe to regular USB functionality, where the chipset is the
> host, and presents itself to the PC as a "usb-storage" class device,
> but this didn't work because the ASM2464PD never enabled the NVMe
> controller (CC.EN bit in BAR0), the PCI Link between the ASM2464PD and
> endpoint function gets up however, and to the host PC the USB device
> is recognized ("usb-storage" class, like a USB stick, e.g., /dev/sda),
> but it cannot be read (shows as 0B block device). As I cannot debug
> the chipset itself I don't know why the NVMe endpoint doesn't get
> enabled. This might very well be a quirk in the ASM2464PD chipset and
> is a very specific use case so I don't think it indicates any major
> issues with the endpoint function, but I report it here for the sake
> of completion.
> 
> I have tested with different storage backend devices for actual
> storage (USB, eMMC, and NVMe (PCIe x1, x2) on the NAS kit).
> 
> In summary, over PCI the endpoint function works well with all three
> Linux/MacOS/Windows hosts.
> 
> Tested-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
> (I don't know if this applies as I co-developed the endpoint function
> with Damien)

I think it does apply since I only tested with Linux hosts. Thanks a lot for all
the extra testing !

Sending v4 with the build failure fixed and doc typos fixed.

> 
> Best regards,
> Rick
> 
> [1] https://wiki.friendlyelec.com/wiki/index.php/CM3588
> [2] https://wiki.friendlyelec.com/wiki/index.php/NanoPC-T6
> [3] https://www.aliexpress.com/item/1005006316029054.html
> [4] https://www.asmedia.com.tw/product/802zX91Yw3tsFgm4/C64ZX59yu4sY1GW5/ASM2464PD
> 


-- 
Damien Le Moal
Western Digital Research