From: Enrico Scholz Date: Thu, 17 Jul 2008 18:09:30 +0000 (+0200) Subject: usb: ISP1760: improve pre-fetch timing X-Git-Tag: v2.6.27-rc4~101^2~20 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=3f02a957d5eb0eeb01207a799086f2b347077f71;p=linux-2.6-omap-h63xx.git 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 Signed-off-by: Sebastian Siewior Signed-off-by: Greg Kroah-Hartman --- 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: diff --git a/drivers/usb/host/isp1760-hcd.h b/drivers/usb/host/isp1760-hcd.h index 6473dd86993..3c61cd51cbb 100644 --- a/drivers/usb/host/isp1760-hcd.h +++ b/drivers/usb/host/isp1760-hcd.h @@ -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)