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USB: ehci-dbgp: split PID register updates for IN and OUT pipes

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This patch addresses two problems:

1) Bulk reads should always use the DATA0 for the pid, and the write
   PID should toggle between DATA0 and DATA1.  The fix is using
   dbgp_pid_write_update() and dbgp_pid_read_update().

2) The delay loop for waiting for a transaction was not long enough to
   always complete the initial handshake inside dbgp_wait_until_done().
   After the initial handshake the maximum delay length is never reached.

The combined result of these two changes allows for the removal of the
forced resynchronization where a bulk write was issued with a dummy
data payload only to get the device to start accepting data writes
again.

CC: Eric Biederman <ebiederm@xmission.com>
CC: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Jason Wessel 2010-02-05 11:49:05 -06:00 committed by Greg Kroah-Hartman
parent 5272098365
commit 815e173e1d
1 changed files with 28 additions and 40 deletions
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68
drivers/usb/early/ehci-dbgp.c
View File

@ -66,8 +66,6 @@ static struct ehci_dev ehci_dev;
#define USB_DEBUG_DEVNUM 127
#define DBGP_DATA_TOGGLE 0x8800
#ifdef DBGP_DEBUG
#define dbgp_printk printk
static void dbgp_ehci_status(char *str)
@ -88,11 +86,6 @@ static inline void dbgp_ehci_status(char *str) { }
static inline void dbgp_printk(const char *fmt, ...) { }
#endif
static inline u32 dbgp_pid_update(u32 x, u32 tok)
{
return ((x ^ DBGP_DATA_TOGGLE) & 0xffff00) | (tok & 0xff);
}
static inline u32 dbgp_len_update(u32 x, u32 len)
{
return (x & ~0x0f) | (len & 0x0f);
@ -136,6 +129,19 @@ static inline u32 dbgp_len_update(u32 x, u32 len)
#define DBGP_MAX_PACKET 8
#define DBGP_TIMEOUT (250 * 1000)
#define DBGP_LOOPS 1000
static inline u32 dbgp_pid_write_update(u32 x, u32 tok)
{
static int data0 = USB_PID_DATA1;
data0 ^= USB_PID_DATA_TOGGLE;
return (x & 0xffff0000) | (data0 << 8) | (tok & 0xff);
}
static inline u32 dbgp_pid_read_update(u32 x, u32 tok)
{
return (x & 0xffff0000) | (USB_PID_DATA0 << 8) | (tok & 0xff);
}
static int dbgp_wait_until_complete(void)
{
@ -180,7 +186,7 @@ static int dbgp_wait_until_done(unsigned ctrl)
{
u32 pids, lpid;
int ret;
int loop = 3;
int loop = DBGP_LOOPS;
retry:
writel(ctrl | DBGP_GO, &ehci_debug->control);
@ -197,6 +203,8 @@ static int dbgp_wait_until_done(unsigned ctrl)
*/
if (ret == -DBGP_TIMEOUT && !dbgp_not_safe)
dbgp_not_safe = 1;
if (ret == -DBGP_ERR_BAD && --loop > 0)
goto retry;
return ret;
}
@ -245,12 +253,20 @@ static inline void dbgp_get_data(void *buf, int size)
bytes[i] = (hi >> (8*(i - 4))) & 0xff;
}
static int dbgp_out(u32 addr, const char *bytes, int size)
static int dbgp_bulk_write(unsigned devnum, unsigned endpoint,
const char *bytes, int size)
{
int ret;
u32 addr;
u32 pids, ctrl;
if (size > DBGP_MAX_PACKET)
return -1;
addr = DBGP_EPADDR(devnum, endpoint);
pids = readl(&ehci_debug->pids);
pids = dbgp_pid_update(pids, USB_PID_OUT);
pids = dbgp_pid_write_update(pids, USB_PID_OUT);
ctrl = readl(&ehci_debug->control);
ctrl = dbgp_len_update(ctrl, size);
@ -260,34 +276,7 @@ static int dbgp_out(u32 addr, const char *bytes, int size)
dbgp_set_data(bytes, size);
writel(addr, &ehci_debug->address);
writel(pids, &ehci_debug->pids);
return dbgp_wait_until_done(ctrl);
}
static int dbgp_bulk_write(unsigned devnum, unsigned endpoint,
const char *bytes, int size)
{
int ret;
int loops = 5;
u32 addr;
if (size > DBGP_MAX_PACKET)
return -1;
addr = DBGP_EPADDR(devnum, endpoint);
try_again:
if (loops--) {
ret = dbgp_out(addr, bytes, size);
if (ret == -DBGP_ERR_BAD) {
int try_loops = 3;
do {
/* Emit a dummy packet to re-sync communication
* with the debug device */
if (dbgp_out(addr, "12345678", 8) >= 0) {
udelay(2);
goto try_again;
}
} while (try_loops--);
}
}
ret = dbgp_wait_until_done(ctrl);
return ret;
}
@ -304,7 +293,7 @@ static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data,
addr = DBGP_EPADDR(devnum, endpoint);
pids = readl(&ehci_debug->pids);
pids = dbgp_pid_update(pids, USB_PID_IN);
pids = dbgp_pid_read_update(pids, USB_PID_IN);
ctrl = readl(&ehci_debug->control);
ctrl = dbgp_len_update(ctrl, size);
@ -362,7 +351,6 @@ static int dbgp_control_msg(unsigned devnum, int requesttype,
return dbgp_bulk_read(devnum, 0, data, size);
}
/* Find a PCI capability */
static u32 __init find_cap(u32 num, u32 slot, u32 func, int cap)
{