[PATCH v4] usb: xhci: fix DMA address corruption in abort_td

[Marek Vasut]

On 1/22/26 6:27 AM, ANANDHAKRISHNAN S wrote:
> When aborting a Transfer Descriptor (TD), the xHCI driver updates the
> device dequeue pointer by converting the virtual enqueue TRB pointer
> into a DMA address.
> 
> Previously, the code OR-ed the ring's Dequeue Cycle State (DCS) bit into
> the virtual TRB pointer before passing it to xhci_trb_virt_to_dma().
> This produced an unaligned virtual address (e.g. ending in 0x...1).
> 
> Inside xhci_trb_virt_to_dma(), the offset calculation:
> 
> segment_offset = trb - seg->trbs;
> 
> operated on this unaligned pointer, resulting in an incorrect TRB index.
> In wraparound cases, this caused the bounds check to fail and the
> function to return 0.
> 
> As a result, a SET_DEQ_PTR command was issued with a DMA address of 0x0,
> leading to controller hangs and transfer timeouts, most commonly when
> aborting TDs near the end of a ring segment (e.g. index 63).
> 
> Fix this by translating the aligned virtual TRB pointer to a DMA address
> first, and only then applying the DCS bit to the resulting physical
> address.
> 
> 
> Signed-off-by: ANANDHAKRISHNAN S <anandhakrishnan.s at dicortech.com>
> ---
> Changes in v4:
> - Moved the changelog below the '---' marker to prevent it from
>    being included in the permanent git history.
Please keep the RB tag next time.

Reviewed-by: Marek Vasut <marek.vasut at mailbox.org>

Applied, thanks.