Re: [PATCH] Revert "usb: renesas-xhci: Fix handling of unknown ROM state"

[Matthias Schiffer]

On 7/19/21 9:05 AM, Moritz Fischer wrote:
> This reverts commit d143825baf15f204dac60acdf95e428182aa3374.
>
> Justin reports some of his systems now fail as result of this commit:
>
>   xhci_hcd 0000:04:00.0: Direct firmware load for renesas_usb_fw.mem failed with error -2
>   xhci_hcd 0000:04:00.0: request_firmware failed: -2
>   xhci_hcd: probe of 0000:04:00.0 failed with error -2
>
> The revert brings back the original issue the commit tried to solve but
> at least unbreaks existing systems relying on previous behavior.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Mathias Nyman <mathias.nyman@xxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Vinod Koul <vkoul@xxxxxxxxxx>
> Cc: Justin Forbes <jmforbes@xxxxxxxxxxx>
> Reported-by: Justin Forbes <jmforbes@xxxxxxxxxxx>
> Signed-off-by: Moritz Fischer <mdf@xxxxxxxxxx>
> ---
>
> Justin,
>
> would you be able to help out testing follow up patches to this?
>
> I don't have a machine to test your use-case and mine definitly requires
> a firmware load on RENESAS_ROM_STATUS_NO_RESULT.
>
> Thanks
> - Moritz


Hi Moritz,

as an additional data point, here's the behaviour of my system, a Thinkpad 
T14 AMD with:

06:00.0 USB controller [0c03]: Renesas Technology Corp. uPD720202 USB 3.0 
Host Controller [1912:0015] (rev 02)

- On Kernel 5.13.1, no firmware: USB controller resets in an endless loop 
when the system is running from battery
- On Kernel 5.13.4, no firmware: USB controller probe fails with the 
mentioned firmware load error
- On Kernel 5.13.4, with renesas_usb_fw.mem: everything is working fine, 
the reset issue is gone

So it seems to me that requiring a firmware is generally the correct driver 
behaviour for this hardware. The firmware I found in the Arch User 
Repository [1] unfortunately has a very restrictive license...

Kind regards,
Matthias


[1] https://github.com/denisandroid/uPD72020x-Firmware



> ---
>   drivers/usb/host/xhci-pci-renesas.c | 16 ++++++++--------
>   1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-pci-renesas.c b/drivers/usb/host/xhci-pci-renesas.c
> index 1da647961c25..5923844ed821 100644
> --- a/drivers/usb/host/xhci-pci-renesas.c
> +++ b/drivers/usb/host/xhci-pci-renesas.c
> @@ -207,8 +207,7 @@ static int renesas_check_rom_state(struct pci_dev *pdev)
>   			return 0;
>   
>   		case RENESAS_ROM_STATUS_NO_RESULT: /* No result yet */
> -			dev_dbg(&pdev->dev, "Unknown ROM status ...\n");
> -			break;
> +			return 0;
>   
>   		case RENESAS_ROM_STATUS_ERROR: /* Error State */
>   		default: /* All other states are marked as "Reserved states" */
> @@ -225,12 +224,13 @@ static int renesas_fw_check_running(struct pci_dev *pdev)
>   	u8 fw_state;
>   	int err;
>   
> -	/*
> -	 * Only if device has ROM and loaded FW we can skip loading and
> -	 * return success. Otherwise (even unknown state), attempt to load FW.
> -	 */
> -	if (renesas_check_rom(pdev) && !renesas_check_rom_state(pdev))
> -		return 0;
> +	/* Check if device has ROM and loaded, if so skip everything */
> +	err = renesas_check_rom(pdev);
> +	if (err) { /* we have rom */
> +		err = renesas_check_rom_state(pdev);
> +		if (!err)
> +			return err;
> +	}
>   
>   	/*
>   	 * Test if the device is actually needing the firmware. As most

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