linux/drivers/usb/host/ehci-mem.c
Karsten Wiese 9aa09d2f8f USB: EHCI: slow down ITD reuse
Currently ITDs are immediately recycled whenever their URB completes.
However, EHCI hardware can sometimes remember some ITD state.  This
means that when the ITD is reused before end-of-frame it may sometimes
cause the hardware to reference bogus state.

This patch defers reusing such ITDs by moving them into a new ehci member
cached_itd_list. ITDs resting in cached_itd_list are moved back into their
stream's free_list once scan_periodic() detects that the active frame has
elapsed.

This makes the snd_usb_us122l driver (in kernel since .28) work right
when it's hooked up through EHCI.

[ dbrownell@users.sourceforge.net: comment fixups ]

Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Tested-by: Philippe Carriere <philippe-f.carriere@wanadoo.fr>
Tested-by: Federico Briata <federicobriata@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-02-27 14:40:50 -08:00

235 lines
6.1 KiB
C

/*
* Copyright (c) 2001 by David Brownell
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/* this file is part of ehci-hcd.c */
/*-------------------------------------------------------------------------*/
/*
* There's basically three types of memory:
* - data used only by the HCD ... kmalloc is fine
* - async and periodic schedules, shared by HC and HCD ... these
* need to use dma_pool or dma_alloc_coherent
* - driver buffers, read/written by HC ... single shot DMA mapped
*
* There's also "register" data (e.g. PCI or SOC), which is memory mapped.
* No memory seen by this driver is pageable.
*/
/*-------------------------------------------------------------------------*/
/* Allocate the key transfer structures from the previously allocated pool */
static inline void ehci_qtd_init(struct ehci_hcd *ehci, struct ehci_qtd *qtd,
dma_addr_t dma)
{
memset (qtd, 0, sizeof *qtd);
qtd->qtd_dma = dma;
qtd->hw_token = cpu_to_le32 (QTD_STS_HALT);
qtd->hw_next = EHCI_LIST_END(ehci);
qtd->hw_alt_next = EHCI_LIST_END(ehci);
INIT_LIST_HEAD (&qtd->qtd_list);
}
static struct ehci_qtd *ehci_qtd_alloc (struct ehci_hcd *ehci, gfp_t flags)
{
struct ehci_qtd *qtd;
dma_addr_t dma;
qtd = dma_pool_alloc (ehci->qtd_pool, flags, &dma);
if (qtd != NULL) {
ehci_qtd_init(ehci, qtd, dma);
}
return qtd;
}
static inline void ehci_qtd_free (struct ehci_hcd *ehci, struct ehci_qtd *qtd)
{
dma_pool_free (ehci->qtd_pool, qtd, qtd->qtd_dma);
}
static void qh_destroy(struct ehci_qh *qh)
{
struct ehci_hcd *ehci = qh->ehci;
/* clean qtds first, and know this is not linked */
if (!list_empty (&qh->qtd_list) || qh->qh_next.ptr) {
ehci_dbg (ehci, "unused qh not empty!\n");
BUG ();
}
if (qh->dummy)
ehci_qtd_free (ehci, qh->dummy);
dma_pool_free (ehci->qh_pool, qh, qh->qh_dma);
}
static struct ehci_qh *ehci_qh_alloc (struct ehci_hcd *ehci, gfp_t flags)
{
struct ehci_qh *qh;
dma_addr_t dma;
qh = (struct ehci_qh *)
dma_pool_alloc (ehci->qh_pool, flags, &dma);
if (!qh)
return qh;
memset (qh, 0, sizeof *qh);
qh->refcount = 1;
qh->ehci = ehci;
qh->qh_dma = dma;
// INIT_LIST_HEAD (&qh->qh_list);
INIT_LIST_HEAD (&qh->qtd_list);
/* dummy td enables safe urb queuing */
qh->dummy = ehci_qtd_alloc (ehci, flags);
if (qh->dummy == NULL) {
ehci_dbg (ehci, "no dummy td\n");
dma_pool_free (ehci->qh_pool, qh, qh->qh_dma);
qh = NULL;
}
return qh;
}
/* to share a qh (cpu threads, or hc) */
static inline struct ehci_qh *qh_get (struct ehci_qh *qh)
{
WARN_ON(!qh->refcount);
qh->refcount++;
return qh;
}
static inline void qh_put (struct ehci_qh *qh)
{
if (!--qh->refcount)
qh_destroy(qh);
}
/*-------------------------------------------------------------------------*/
/* The queue heads and transfer descriptors are managed from pools tied
* to each of the "per device" structures.
* This is the initialisation and cleanup code.
*/
static void ehci_mem_cleanup (struct ehci_hcd *ehci)
{
free_cached_itd_list(ehci);
if (ehci->async)
qh_put (ehci->async);
ehci->async = NULL;
/* DMA consistent memory and pools */
if (ehci->qtd_pool)
dma_pool_destroy (ehci->qtd_pool);
ehci->qtd_pool = NULL;
if (ehci->qh_pool) {
dma_pool_destroy (ehci->qh_pool);
ehci->qh_pool = NULL;
}
if (ehci->itd_pool)
dma_pool_destroy (ehci->itd_pool);
ehci->itd_pool = NULL;
if (ehci->sitd_pool)
dma_pool_destroy (ehci->sitd_pool);
ehci->sitd_pool = NULL;
if (ehci->periodic)
dma_free_coherent (ehci_to_hcd(ehci)->self.controller,
ehci->periodic_size * sizeof (u32),
ehci->periodic, ehci->periodic_dma);
ehci->periodic = NULL;
/* shadow periodic table */
kfree(ehci->pshadow);
ehci->pshadow = NULL;
}
/* remember to add cleanup code (above) if you add anything here */
static int ehci_mem_init (struct ehci_hcd *ehci, gfp_t flags)
{
int i;
/* QTDs for control/bulk/intr transfers */
ehci->qtd_pool = dma_pool_create ("ehci_qtd",
ehci_to_hcd(ehci)->self.controller,
sizeof (struct ehci_qtd),
32 /* byte alignment (for hw parts) */,
4096 /* can't cross 4K */);
if (!ehci->qtd_pool) {
goto fail;
}
/* QHs for control/bulk/intr transfers */
ehci->qh_pool = dma_pool_create ("ehci_qh",
ehci_to_hcd(ehci)->self.controller,
sizeof (struct ehci_qh),
32 /* byte alignment (for hw parts) */,
4096 /* can't cross 4K */);
if (!ehci->qh_pool) {
goto fail;
}
ehci->async = ehci_qh_alloc (ehci, flags);
if (!ehci->async) {
goto fail;
}
/* ITD for high speed ISO transfers */
ehci->itd_pool = dma_pool_create ("ehci_itd",
ehci_to_hcd(ehci)->self.controller,
sizeof (struct ehci_itd),
32 /* byte alignment (for hw parts) */,
4096 /* can't cross 4K */);
if (!ehci->itd_pool) {
goto fail;
}
/* SITD for full/low speed split ISO transfers */
ehci->sitd_pool = dma_pool_create ("ehci_sitd",
ehci_to_hcd(ehci)->self.controller,
sizeof (struct ehci_sitd),
32 /* byte alignment (for hw parts) */,
4096 /* can't cross 4K */);
if (!ehci->sitd_pool) {
goto fail;
}
/* Hardware periodic table */
ehci->periodic = (__le32 *)
dma_alloc_coherent (ehci_to_hcd(ehci)->self.controller,
ehci->periodic_size * sizeof(__le32),
&ehci->periodic_dma, 0);
if (ehci->periodic == NULL) {
goto fail;
}
for (i = 0; i < ehci->periodic_size; i++)
ehci->periodic [i] = EHCI_LIST_END(ehci);
/* software shadow of hardware table */
ehci->pshadow = kcalloc(ehci->periodic_size, sizeof(void *), flags);
if (ehci->pshadow != NULL)
return 0;
fail:
ehci_dbg (ehci, "couldn't init memory\n");
ehci_mem_cleanup (ehci);
return -ENOMEM;
}