[PATCH] usb: xhci: Fix compare to use physical addresses in xhci_bulk_tx()

[Stefan Roese]

On 15.01.21 11:27, Nicolas Saenz Julienne wrote:
> On Fri, 2021-01-15 at 08:52 +0100, Stefan Roese wrote:
>> Testing with v2021.01 on MIPS Octeon has shown, that the latest patch
>> for the "short packet event trb handling" did introduce a bug on
>> platforms with virtual address != physical address. This patch fixes
>> this issue by using the correct address types in the compare (both
>> physical in this case).
>>
>> Signed-off-by: Stefan Roese <sr at denx.de>
>> Cc: Aaron Williams <awilliams at marvell.com>
>> Cc: Chandrakala Chavva <cchavva at marvell.com>
>> Cc: Ran Wang <ran.wang_1 at nxp.com>
>> Cc: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>
>> Cc: Marek Vasut <marex at denx.de>
>> Cc: Bin Meng <bmeng.cn at gmail.com>
>> ---
>>   drivers/usb/host/xhci-ring.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
>> index d708fc928b..d6c47d579b 100644
>> --- a/drivers/usb/host/xhci-ring.c
>> +++ b/drivers/usb/host/xhci-ring.c
>> @@ -723,8 +723,8 @@ again:
>>   		return -ETIMEDOUT;
>>   	}
>>   
>>
>> -	if ((uintptr_t)(le64_to_cpu(event->trans_event.buffer))
>> -			!= (uintptr_t)last_transfer_trb_addr) {
>> +	if ((uintptr_t)(le64_to_cpu(event->trans_event.buffer)) !=
>> +	    (uintptr_t)virt_to_phys(last_transfer_trb_addr)) {
>>   		available_length -=
>>   			(int)EVENT_TRB_LEN(le32_to_cpu(event->trans_event.transfer_len));
>>   		xhci_acknowledge_event(ctrl);
> 
> FWIW I also addressed this in my Rpi400/CM4 enablement series:
> https://lists.denx.de/pipermail/u-boot/2021-January/437150.html

Yes, thanks. I've seen your patch and also looked into it while
debugging this issue on my MIPS platform this morning.

Actually I would prefer my fix, as it uses virt_to_phys() and not the
other way around. Currently only virt_to_phys() is used in the USB code
and not phys_to_virt(), which does not seem to work correctly on my
platform BTW (as I discovered this morning).

> That said,
> 
> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>

Thanks,
Stefan