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authorEnrico Scholz <enrico.scholz@sigma-chemnitz.de>2008-07-17 20:09:30 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2008-08-13 17:32:53 -0700
commit3f02a957d5eb0eeb01207a799086f2b347077f71 (patch)
tree1e163aaabe6b260a168ab3c4744066d471f75fb4 /drivers/usb/host/isp1760-hcd.c
parenta36c27dfd1003e6d6842fe77faaf868e3e6e9062 (diff)
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>
Diffstat (limited to 'drivers/usb/host/isp1760-hcd.c')
-rw-r--r--drivers/usb/host/isp1760-hcd.c44
1 files changed, 31 insertions, 13 deletions
diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c
index db5f4f5c7a1..e209b3b709d 100644
--- a/drivers/usb/host/isp1760-hcd.c
+++ b/drivers/usb/host/isp1760-hcd.c
@@ -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: