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yaml
---
r: 264895
b: refs/heads/master
c: 6d50c60
h: refs/heads/master
i:
  264893: f2d80a5
  264891: 746667f
  264887: 8168637
  264879: 6688c6a
  264863: 16b6b66
  264831: 9291335
v: v3
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Arvid Brodin authored and Greg Kroah-Hartman committed Aug 22, 2011
1 parent d3c95a4 commit 76898ac
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Showing 3 changed files with 97 additions and 46 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 0ba7905e030a409fd0bb92cb965e915c0cb01030
refs/heads/master: 6d50c60e6d169b04b0cf0b267eb14ab0839f9540
138 changes: 94 additions & 44 deletions trunk/drivers/usb/host/isp1760-hcd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/timer.h>
#include <asm/unaligned.h>
#include <asm/cacheflush.h>

Expand All @@ -39,7 +40,6 @@ struct isp1760_hcd {
int int_done_map;
struct memory_chunk memory_pool[BLOCKS];
struct list_head controlqhs, bulkqhs, interruptqhs;
int active_ptds;

/* periodic schedule support */
#define DEFAULT_I_TDPS 1024
Expand Down Expand Up @@ -489,10 +489,6 @@ static int isp1760_hc_setup(struct usb_hcd *hcd)
16 : 32, (priv->devflags & ISP1760_FLAG_ANALOG_OC) ?
"analog" : "digital");

/* This is weird: at the first plug-in of a device there seems to be
one packet queued that never gets returned? */
priv->active_ptds = -1;

/* ATL reset */
reg_write32(hcd->regs, HC_HW_MODE_CTRL, hwmode | ALL_ATX_RESET);
mdelay(10);
Expand Down Expand Up @@ -741,8 +737,8 @@ static void start_bus_transfer(struct usb_hcd *hcd, u32 ptd_offset, int slot,
qh->slot = slot;
qtd->status = QTD_XFER_STARTED; /* Set this before writing ptd, since
interrupt routine may preempt and expects this value. */
slots[slot].timestamp = jiffies;
ptd_write(hcd->regs, ptd_offset, slot, ptd);
priv->active_ptds++;

/* Make sure done map has not triggered from some unlinked transfer */
if (ptd_offset == ATL_PTD_OFFSET) {
Expand Down Expand Up @@ -1091,11 +1087,9 @@ static int check_atl_transfer(struct usb_hcd *hcd, struct ptd *ptd,
return PTD_STATE_QTD_DONE;
}

static irqreturn_t isp1760_irq(struct usb_hcd *hcd)
static void handle_done_ptds(struct usb_hcd *hcd)
{
struct isp1760_hcd *priv = hcd_to_priv(hcd);
u32 imask;
irqreturn_t irqret = IRQ_NONE;
struct ptd ptd;
struct isp1760_qh *qh;
int slot;
Expand All @@ -1104,27 +1098,14 @@ static irqreturn_t isp1760_irq(struct usb_hcd *hcd)
u32 ptd_offset;
struct isp1760_qtd *qtd;
int modified;
static int last_active_ptds;
int int_skip_map, atl_skip_map;

spin_lock(&priv->lock);

if (!(hcd->state & HC_STATE_RUNNING))
goto leave;

imask = reg_read32(hcd->regs, HC_INTERRUPT_REG);
if (unlikely(!imask))
goto leave;
reg_write32(hcd->regs, HC_INTERRUPT_REG, imask); /* Clear */
int skip_map;

int_skip_map = reg_read32(hcd->regs, HC_INT_PTD_SKIPMAP_REG);
atl_skip_map = reg_read32(hcd->regs, HC_ATL_PTD_SKIPMAP_REG);
priv->int_done_map |= reg_read32(hcd->regs, HC_INT_PTD_DONEMAP_REG);
priv->atl_done_map |= reg_read32(hcd->regs, HC_ATL_PTD_DONEMAP_REG);
priv->int_done_map &= ~int_skip_map;
priv->atl_done_map &= ~atl_skip_map;
skip_map = reg_read32(hcd->regs, HC_INT_PTD_SKIPMAP_REG);
priv->int_done_map &= ~skip_map;
skip_map = reg_read32(hcd->regs, HC_ATL_PTD_SKIPMAP_REG);
priv->atl_done_map &= ~skip_map;

modified = priv->int_done_map | priv->atl_done_map;
modified = priv->int_done_map || priv->atl_done_map;

while (priv->int_done_map || priv->atl_done_map) {
if (priv->int_done_map) {
Expand Down Expand Up @@ -1163,7 +1144,6 @@ static irqreturn_t isp1760_irq(struct usb_hcd *hcd)
slots[slot].qtd = NULL;
qh = slots[slot].qh;
slots[slot].qh = NULL;
priv->active_ptds--;
qh->slot = -1;

WARN_ON(qtd->status != QTD_XFER_STARTED);
Expand Down Expand Up @@ -1234,22 +1214,28 @@ static irqreturn_t isp1760_irq(struct usb_hcd *hcd)

if (modified)
schedule_ptds(hcd);
}

/* ISP1760 Errata 2 explains that interrupts may be missed (or not
happen?) if two USB devices are running simultaneously. Perhaps
this happens when a PTD is finished during interrupt handling;
enable SOF interrupts if PTDs are still scheduled when exiting this
interrupt handler, just to be safe. */
static irqreturn_t isp1760_irq(struct usb_hcd *hcd)
{
struct isp1760_hcd *priv = hcd_to_priv(hcd);
u32 imask;
irqreturn_t irqret = IRQ_NONE;

if (priv->active_ptds != last_active_ptds) {
if (priv->active_ptds > 0)
reg_write32(hcd->regs, HC_INTERRUPT_ENABLE,
INTERRUPT_ENABLE_SOT_MASK);
else
reg_write32(hcd->regs, HC_INTERRUPT_ENABLE,
INTERRUPT_ENABLE_MASK);
last_active_ptds = priv->active_ptds;
}
spin_lock(&priv->lock);

if (!(hcd->state & HC_STATE_RUNNING))
goto leave;

imask = reg_read32(hcd->regs, HC_INTERRUPT_REG);
if (unlikely(!imask))
goto leave;
reg_write32(hcd->regs, HC_INTERRUPT_REG, imask); /* Clear */

priv->int_done_map |= reg_read32(hcd->regs, HC_INT_PTD_DONEMAP_REG);
priv->atl_done_map |= reg_read32(hcd->regs, HC_ATL_PTD_DONEMAP_REG);

handle_done_ptds(hcd);

irqret = IRQ_HANDLED;
leave:
Expand All @@ -1258,6 +1244,63 @@ static irqreturn_t isp1760_irq(struct usb_hcd *hcd)
return irqret;
}

/*
* Workaround for problem described in chip errata 2:
*
* Sometimes interrupts are not generated when ATL (not INT?) completion occurs.
* One solution suggested in the errata is to use SOF interrupts _instead_of_
* ATL done interrupts (the "instead of" might be important since it seems
* enabling ATL interrupts also causes the chip to sometimes - rarely - "forget"
* to set the PTD's done bit in addition to not generating an interrupt!).
*
* So if we use SOF + ATL interrupts, we sometimes get stale PTDs since their
* done bit is not being set. This is bad - it blocks the endpoint until reboot.
*
* If we use SOF interrupts only, we get latency between ptd completion and the
* actual handling. This is very noticeable in testusb runs which takes several
* minutes longer without ATL interrupts.
*
* A better solution is to run the code below every SLOT_CHECK_PERIOD ms. If it
* finds active ATL slots which are older than SLOT_TIMEOUT ms, it checks the
* slot's ACTIVE and VALID bits. If these are not set, the ptd is considered
* completed and its done map bit is set.
*
* The values of SLOT_TIMEOUT and SLOT_CHECK_PERIOD have been arbitrarily chosen
* not to cause too much lag when this HW bug occurs, while still hopefully
* ensuring that the check does not falsely trigger.
*/
#define SLOT_TIMEOUT 180
#define SLOT_CHECK_PERIOD 200
static struct timer_list errata2_timer;

void errata2_function(unsigned long data)
{
struct usb_hcd *hcd = (struct usb_hcd *) data;
struct isp1760_hcd *priv = hcd_to_priv(hcd);
int slot;
struct ptd ptd;
unsigned long spinflags;

spin_lock_irqsave(&priv->lock, spinflags);

for (slot = 0; slot < 32; slot++)
if ((priv->atl_slots[slot].qh || priv->atl_slots[slot].qtd) &&
time_after(jiffies + SLOT_TIMEOUT * HZ / 1000,
priv->atl_slots[slot].timestamp)) {
ptd_read(hcd->regs, ATL_PTD_OFFSET, slot, &ptd);
if (!FROM_DW0_VALID(ptd.dw0) &&
!FROM_DW3_ACTIVE(ptd.dw3))
priv->atl_done_map |= 1 << slot;
}

handle_done_ptds(hcd);

spin_unlock_irqrestore(&priv->lock, spinflags);

errata2_timer.expires = jiffies + SLOT_CHECK_PERIOD * HZ / 1000;
add_timer(&errata2_timer);
}

static int isp1760_run(struct usb_hcd *hcd)
{
int retval;
Expand Down Expand Up @@ -1303,6 +1346,12 @@ static int isp1760_run(struct usb_hcd *hcd)
if (retval)
return retval;

init_timer(&errata2_timer);
errata2_timer.function = errata2_function;
errata2_timer.data = (unsigned long) hcd;
errata2_timer.expires = jiffies + SLOT_CHECK_PERIOD * HZ / 1000;
add_timer(&errata2_timer);

chipid = reg_read32(hcd->regs, HC_CHIP_ID_REG);
dev_info(hcd->self.controller, "USB ISP %04x HW rev. %d started\n",
chipid & 0xffff, chipid >> 16);
Expand Down Expand Up @@ -1561,7 +1610,6 @@ static void kill_transfer(struct usb_hcd *hcd, struct urb *urb,
}

qh->slot = -1;
priv->active_ptds--;
}

static int isp1760_urb_dequeue(struct usb_hcd *hcd, struct urb *urb,
Expand Down Expand Up @@ -2012,6 +2060,8 @@ static void isp1760_stop(struct usb_hcd *hcd)
struct isp1760_hcd *priv = hcd_to_priv(hcd);
u32 temp;

del_timer(&errata2_timer);

isp1760_hub_control(hcd, ClearPortFeature, USB_PORT_FEAT_POWER, 1,
NULL, 0);
mdelay(20);
Expand Down
3 changes: 2 additions & 1 deletion trunk/drivers/usb/host/isp1760-hcd.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -73,7 +73,6 @@ void deinit_kmem_cache(void);
#define HC_EOT_INT (1 << 3)
#define HC_SOT_INT (1 << 1)
#define INTERRUPT_ENABLE_MASK (HC_INTL_INT | HC_ATL_INT)
#define INTERRUPT_ENABLE_SOT_MASK (HC_SOT_INT)

#define HC_ISO_IRQ_MASK_OR_REG 0x318
#define HC_INT_IRQ_MASK_OR_REG 0x31C
Expand Down Expand Up @@ -107,6 +106,7 @@ struct ptd {
struct slotinfo {
struct isp1760_qh *qh;
struct isp1760_qtd *qtd;
unsigned long timestamp;
};


Expand Down Expand Up @@ -188,6 +188,7 @@ struct memory_chunk {
#define DW3_BABBLE_BIT (1 << 29)
#define DW3_HALT_BIT (1 << 30)
#define DW3_ACTIVE_BIT (1 << 31)
#define FROM_DW3_ACTIVE(x) (((x) >> 31) & 0x01)

#define INT_UNDERRUN (1 << 2)
#define INT_BABBLE (1 << 1)
Expand Down

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