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| author | Enrico Scholz <enrico.scholz@sigma-chemnitz.de> | 2008-07-17 20:09:30 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-08-14 02:32:53 +0200 |
| commit | 3f02a957d5eb0eeb01207a799086f2b347077f71 (patch) | |
| tree | 1e163aaabe6b260a168ab3c4744066d471f75fb4 /drivers/usb/host/isp1760-hcd.h | |
| parent | usb: return error code instead of 0 in the enqueue function. (diff) | |
| download | linux-3f02a957d5eb0eeb01207a799086f2b347077f71.tar.xz linux-3f02a957d5eb0eeb01207a799086f2b347077f71.zip | |
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 '')
| -rw-r--r-- | drivers/usb/host/isp1760-hcd.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/host/isp1760-hcd.h b/drivers/usb/host/isp1760-hcd.h index 6473dd86993c..3c61cd51cbb8 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) |