Re: [PATCH v6] usb-storage,uas: use host helper to generate driver info

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Nov 05, 2023 at 07:20:47PM +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@gmail.com/
> 
> 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@gmail.com>

I see the need for this, but why now?  We haven't run out of ids yet
have we?  Do we need to add another one?

Also, after building, I get the following files marked by git as needed
to be added to the tree, so perhaps you also need a .gitignore file:

$ git status
On branch work-testing
Untracked files:
  (use "git add <file>..." to include in what will be committed)
	drivers/usb/storage/mkflags
	drivers/usb/storage/usb-ids-uas.c
	drivers/usb/storage/usb-ids.c

thanks,

greg k-h