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: Enrico Scholz <enrico.scholz@sigma-chemnitz.de>
Signed-off-by: Sebastian Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c
index db5f4f5..e209b3b 100644
--- a/drivers/usb/host/isp1760-hcd.c
+++ b/drivers/usb/host/isp1760-hcd.c
@@ -126,9 +126,8 @@
* 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 @@
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 @@
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 @@
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 @@
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 @@
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:
diff --git a/drivers/usb/host/isp1760-hcd.h b/drivers/usb/host/isp1760-hcd.h
index 6473dd8..3c61cd5 100644
--- a/drivers/usb/host/isp1760-hcd.h
+++ b/drivers/usb/host/isp1760-hcd.h
@@ -54,6 +54,8 @@
#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)