Subject: Re: USB stack needs early review (Re: Someone should fix our USB stack...)
To: None <tech-kern@netbsd.org>
From: ITOH Yasufumi <itohy@netbsd.org>
List: tech-kern
Date: 03/28/2007 23:07:27
Hello,
Here's today's version waiting for review.
What's new:
- test uhci(4) and fix some bugs
- add memory alloc/dealloc tracing code (USBMEM_DEBUG: enabled by default)
- fix memory leaks in ohci(4), probably also in ehci(4) and uhci(4),
which are also fixed
- add diagnostic panics for resource allocation on interrupt context.
- fix umass(4) to allocate resources beforehand (found by the diag panic
above)
- usb.h: add UE_MAXPKTSZ(ep) and UE_MAXPKTSZ_MASK macros (for high-speed
isochronous devices)
- still it sometimes panics, however
ftp://ftp.netbsd.org/pub/NetBSD/misc/itohy/usbtest-20070328.tar.gz
This applies to NetBSD 4.99.13 (before caddr_t removal).
Started based on FreeBSD version, excluding
- removal of portability code
Patch most NetBSD changes, excluding
- DMA memory "reserve"
- caddr_t removal, expecting it will soon be reverted :D
- volatiles in DMA structure, since it should not be needed
with proper bus_dmamap_sync(9)s
DMA/non-DMA memory management overhaul
- Move all DMA related code to usb_mem.[ch]
(add usb_alloc_buffer_dma(), usb_free_buffer_dma(), etc.).
XXX Should usb_mem.[ch] be renamed as usb_mem_dma.[ch] ?
- Add corresponding non-DMA code to usb_mem_nodma.[ch] .
Currently just use malloc(9).
- Above files are conditionally used by config framework (added
attributes to conf/files and dev/usb/files.usb).
- Add diagnostic panics when resource allocation is requested
on interrupt context.
Allocate DMA/non-DMA buffer per host interface, not globally.
advantage: Buffers can be freed on detaching host interface.
Activity of a host interface does not affect others.
disadvantages: It possibly consumes more memory.
API changes
- no visible changes to USB driver interface
- async request will be processed as a task (kernel thread context),
and delayed to some extent
- usbdivar.h: struct usbd_xfer: renamed a member "allocbuf" to "hcbuffer"
(mapped/allocated/refered buffer for HCI driver)
- usb_port.h: change usb_proc_ptr from struct ptoc * to struct lwp *
- usb_port.h: add usb_sigproc_ptr for psignal(9) (struct proc *)
- usb.h: add UE_MAXPKTSZ(ep) and UE_MAXPKTSZ_MASK macros for USB 2.0
changed to USB device drivers
- umass: allocate memory beforehand to avoid resource allocation on
callback (interrupt context)
ohci
- free resources on detach
- add lots of bus_dmamap_sync() operations
- simplify the code of loading std chain
- rewrite code of looking up TD/ITD from DMA addr by using allocation chunk
- add workaround for CMD Tech 670 and 673 chipsets
slhci
- allocate xfer and slhci_xfer at once, and simplify relevant code
- add slhci_detach()
- remove second arg of slhci_attach() since it is the same as the first arg.
- NOT TESTED, missing hardware
ehci
- add lots of bus_dmamap_sync() operations, possibly too many
- NOT TESTED, missing hardware
uhci
- add lots of bus_dmamap_sync() operations, possibly too many
To do
- review, test, debug
- still possibility left to allocate memory in interrupt context --- should
be fixed (by ad hoc manner or whole redesign?)
Christos Zoulas writes:
> In article <200703221525.l2MFP1GX013433@v057181.ppp.asahi-net.or.jp>,
> ITOH Yasufumi <itohy@netbsd.org> wrote:
>
> >Patch most NetBSD changes, excluding
> > - DMA memory "reserve"
> > - caddr_t removal, expecting it will soon be reverted :D
>
> It will be a cold day in hell :-)
No one shall be against to have caddr_t since Solaris has it.
:-)
--
ITOH Yasufumi