On 11/3/23 21:30, Alan Stern wrote:
On Fri, Nov 03, 2023 at 09:17:09PM +0100, Milan Broz wrote:
The USB mass storage quirks flags can be stored in driver_info in
a 32-bit integer (unsigned long on 32-bit platforms).
As this attribute cannot be enlarged, we need to use some form
of translation of 64-bit quirk bits.
This problem was discussed on the USB list
https://lore.kernel.org/linux-usb/f9e8acb5-32d5-4a30-859f-d4336a86b31a@xxxxxxxxx/
The initial solution to use a static array extensively increased the size
of the kernel module, so I decided to try the second suggested solution:
generate a table by host-compiled program and use bit 31 to indicate
that the value is an index, not the actual value.
This patch adds a host-compiled program that processes unusual_devs.h
(and unusual_uas.h) and generates files usb-ids.c and usb-ids-uas.c
(for pre-processed USB device table with 32-bit device info).
These files also contain a generated translation table for driver_info
to 64-bit values.
The translation function is used only in usb-storage and uas modules; all
other USB storage modules store flags directly, using only 32-bit flags.
For 64-bit platforms, where unsigned long is 64-bit, we do not need to
convert quirk flags to 32-bit index; the translation function there uses
flags directly.
Signed-off-by: Milan Broz <gmazyland@xxxxxxxxx>
---
Reviewed-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Thanks.
Unfortunately, the build rules, I removed in this version, are needed, see
https://lore.kernel.org/oe-kbuild-all/202311041507.AOYwj5tK-lkp@xxxxxxxxx/
I'll keep fixed version in my branch on kernel.org for a day and once
there are no such bot reports, new version v6 appears in the list.
Thanks,
Milan
