[PATCH v3 0/2] usb: xhci: page size improvements

Niklas Neronin
2025-02-04T12:43:09Z

Correct off-by-one page size debug message.
Set page size to the xHCI-supported size, instead of 4KB.

Clarified the interpretation of the xHCI spec 1.9 regarding page size.
The correct interpretation is that only one bit is set, indicating the
only supported page size. This is supported by the following sources:

Section 6.6.1, PSZ:
The PSZ calculation uses the page size bit and would not work with
multiple bits set.

Section 7.7, Implementation Notes:
"This version of the xHCI spec only allows an implementation to support
a single page size, as reported by the PAGESIZE register."

Version 3 changes:
* Rebase agains Linux 6.14-rc1.
* Repalce variable int 'i' with unsigned int 'val'.
* Rename temp variable 'page_shift' to 'page_size'.
Version 2 changes:
* Added handling for invalid page size register values.

Niklas Neronin (2):
usb: xhci: correct debug message page size calculation
usb: xhci: set page size to the xHCI-supported size

drivers/usb/host/xhci-mem.c | 34 ++++++++++++++++++----------------
drivers/usb/host/xhci.h | 8 ++++----
2 files changed, 22 insertions(+), 20 deletions(-)

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2.47.2