[PATCH v1 2/8] usb: xhci: xhci_bulk_tx: Don't "BUG" when comparing addresses on Octeon

[Stefan Roese]

On 19.08.20 15:49, Daniel Schwierzeck wrote:
> Am Montag, den 17.08.2020, 15:06 +0200 schrieb Stefan Roese:
>> Octeon uses mapped addresses for virtual and physical memory. Its not
>> that easy to calculate the resulting addresses here. So lets remove
>> this BUG_ON() for Octeon in xhci_bulk_tx().
>>
>> Signed-off-by: Stefan Roese <sr at denx.de>
>> Cc: Bin Meng <bmeng.cn at gmail.com>
>> Cc: Marek Vasut <marex at denx.de>
>> ---
>>
>>   drivers/usb/host/xhci-ring.c | 7 +++++--
>>   1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
>> index 092ed6eaf1..a762177c57 100644
>> --- a/drivers/usb/host/xhci-ring.c
>> +++ b/drivers/usb/host/xhci-ring.c
>> @@ -726,8 +726,11 @@ int xhci_bulk_tx(struct usb_device *udev, unsigned long pipe,
>>   
>>   	BUG_ON(TRB_TO_SLOT_ID(field) != slot_id);
>>   	BUG_ON(TRB_TO_EP_INDEX(field) != ep_index);
>> -	BUG_ON(*(void **)(uintptr_t)le64_to_cpu(event->trans_event.buffer) -
>> -		buffer > (size_t)length);
>> +	if (!IS_ENABLED(CONFIG_ARCH_OCTEON)) {
>> +			BUG_ON(*(void **)(uintptr_t)le64_to_cpu(
>> +				       event->trans_event.buffer) - buffer >
>> +			       (size_t)length);
>> +	}
> 
> why not remove the check? Or add at least a generic Kconfig option for
> special handling on archs with memory remapping. Arch or SoC specific
> config options in generic code are bad ;)

Yes, I agree. I was also thinking about removing this check completely.
I'm not 100% sure, but I think that some (most?) of these BUG_ON()
macros have been removed from the Linux kernel.

To not make too many changes, I'll change this patch in the next
version to just remove this one BUG_ON().

Thanks,
Stefan