提交 3f02a957 编写于 作者: E Enrico Scholz 提交者: Greg Kroah-Hartman

usb: ISP1760: improve pre-fetch timing

ISP1760 requires a delay of 90ns between programming the address and
reading the data.  Current driver solves this by a mdelay(1) which is
very heavy weighted and slow.  This patch applies the workaround from
the ISP1760 FAQ by using two different banks for PTD and payload data
and using a common wait for them.  This wait is done by an additional
ISP1760 access (whose timing constraints guarantee the 90ns delay).
This improves speed when reading from an USB stick from:

  $ time dd if=/dev/sda of=/dev/zero bs=65536 count=1638
  real    1m 15.43s
  user    0m 0.44s
  sys     0m 39.46s

to

  $ time dd if=/dev/sda of=/dev/zero bs=65536 count=1638
  real    0m 18.53s
  user    0m 0.16s
  sys     0m 12.97s

[bigeasy@linutronix.de: fixed comment formating, moved define into
   header file, obey 80 char rule]
Signed-off-by: NEnrico Scholz <enrico.scholz@sigma-chemnitz.de>
Signed-off-by: NSebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
上级 a36c27df
......@@ -126,9 +126,8 @@ static void isp1760_writel(const unsigned int val, __u32 __iomem *regs)
* doesn't quite work because some people have to enforce 32-bit access
*/
static void priv_read_copy(struct isp1760_hcd *priv, u32 *src,
__u32 __iomem *dst, u32 offset, u32 len)
__u32 __iomem *dst, u32 len)
{
struct usb_hcd *hcd = priv_to_hcd(priv);
u32 val;
u8 *buff8;
......@@ -136,11 +135,6 @@ static void priv_read_copy(struct isp1760_hcd *priv, u32 *src,
printk(KERN_ERR "ERROR: buffer: %p len: %d\n", src, len);
return;
}
isp1760_writel(offset, hcd->regs + HC_MEMORY_REG);
/* XXX
* 90nsec delay, the spec says something how this could be avoided.
*/
mdelay(1);
while (len >= 4) {
*src = __raw_readl(dst);
......@@ -987,8 +981,20 @@ static void do_atl_int(struct usb_hcd *usb_hcd)
printk(KERN_ERR "qh is 0\n");
continue;
}
priv_read_copy(priv, (u32 *)&ptd, usb_hcd->regs + atl_regs,
atl_regs, sizeof(ptd));
isp1760_writel(atl_regs + ISP_BANK(0), usb_hcd->regs +
HC_MEMORY_REG);
isp1760_writel(payload + ISP_BANK(1), usb_hcd->regs +
HC_MEMORY_REG);
/*
* write bank1 address twice to ensure the 90ns delay (time
* between BANK0 write and the priv_read_copy() call is at
* least 3*t_WHWL + 2*t_w11 = 3*25ns + 2*17ns = 92ns)
*/
isp1760_writel(payload + ISP_BANK(1), usb_hcd->regs +
HC_MEMORY_REG);
priv_read_copy(priv, (u32 *)&ptd, usb_hcd->regs + atl_regs +
ISP_BANK(0), sizeof(ptd));
dw1 = le32_to_cpu(ptd.dw1);
dw2 = le32_to_cpu(ptd.dw2);
......@@ -1091,7 +1097,7 @@ static void do_atl_int(struct usb_hcd *usb_hcd)
case IN_PID:
priv_read_copy(priv,
priv->atl_ints[queue_entry].data_buffer,
usb_hcd->regs + payload, payload,
usb_hcd->regs + payload + ISP_BANK(1),
length);
case OUT_PID:
......@@ -1206,8 +1212,20 @@ static void do_intl_int(struct usb_hcd *usb_hcd)
continue;
}
priv_read_copy(priv, (u32 *)&ptd, usb_hcd->regs + int_regs,
int_regs, sizeof(ptd));
isp1760_writel(int_regs + ISP_BANK(0), usb_hcd->regs +
HC_MEMORY_REG);
isp1760_writel(payload + ISP_BANK(1), usb_hcd->regs +
HC_MEMORY_REG);
/*
* write bank1 address twice to ensure the 90ns delay (time
* between BANK0 write and the priv_read_copy() call is at
* least 3*t_WHWL + 2*t_w11 = 3*25ns + 2*17ns = 92ns)
*/
isp1760_writel(payload + ISP_BANK(1), usb_hcd->regs +
HC_MEMORY_REG);
priv_read_copy(priv, (u32 *)&ptd, usb_hcd->regs + int_regs +
ISP_BANK(0), sizeof(ptd));
dw1 = le32_to_cpu(ptd.dw1);
dw3 = le32_to_cpu(ptd.dw3);
check_int_err_status(le32_to_cpu(ptd.dw4));
......@@ -1242,7 +1260,7 @@ static void do_intl_int(struct usb_hcd *usb_hcd)
case IN_PID:
priv_read_copy(priv,
priv->int_ints[queue_entry].data_buffer,
usb_hcd->regs + payload , payload,
usb_hcd->regs + payload + ISP_BANK(1),
length);
case OUT_PID:
......
......@@ -54,6 +54,8 @@ void deinit_kmem_cache(void);
#define BUFFER_MAP 0x7
#define HC_MEMORY_REG 0x33c
#define ISP_BANK(x) ((x) << 16)
#define HC_PORT1_CTRL 0x374
#define PORT1_POWER (3 << 3)
#define PORT1_INIT1 (1 << 7)
......
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