Bug 3604 - HS_USECS / HS_USECS_ISO in drivers/usb/core/hcd.h is incorrect
Summary: HS_USECS / HS_USECS_ISO in drivers/usb/core/hcd.h is incorrect
Status: RESOLVED CODE_FIX
Alias: None
Product: Drivers
Classification: Unclassified
Component: USB (show other bugs)
Hardware: i386 Linux
: P2 low
Assignee: David Brownell
URL:
Keywords:
Depends on:
Blocks: USB
  Show dependency tree
 
Reported: 2004-10-20 22:43 UTC by Huah Tu
Modified: 2005-08-18 21:37 UTC (History)
1 user (show)

See Also:
Kernel Version: 2.6.9
Subsystem:
Regression: ---
Bisected commit-id:

Attachments
2.6.13-rc4 patch (1.07 KB, patch)
2005-08-02 14:39 UTC, David Brownell 		Details | Diff
Add an attachment (proposed patch, testcase, etc.)

Description Huah Tu 2004-10-20 22:43:16 UTC 
from Linux 2.4.22 --> 2.6.9, HS_USECS / HS_USECS_ISO are defined as
#define HS_USECS(bytes) NS_TO_US ( ((55 * 8 * 2083)/1000) \
	+ ((2083UL * (3167 + BitTime (bytes)))/1000) \
	+ USB2_HOST_DELAY)
#define HS_USECS_ISO(bytes) NS_TO_US ( ((38 * 8 * 2083)/1000) \
	+ ((2083UL * (3167 + BitTime (bytes)))/1000) \
	+ USB2_HOST_DELAY)
no matter from USB 2.0 spec., or other calculations in usb_calc_bus_time(), 
the term ((2083UL * (3167 + BitTime (bytes)))/1000) is wrong, it is not close 
to (2.083 * (3.167 + BitTime (bytes))).
Comment 1 David Brownell 2004-11-10 15:59:24 UTC 
Feel free to submit a patch that can be reviewed ...
Comment 2 David Brownell 2004-11-18 23:09:36 UTC 
low priority bug, the high speed scheduling code doesn't even 
share entries yet.
Comment 3 David Brownell 2005-08-02 14:39:16 UTC 
Created attachment 5484 [details]
2.6.13-rc4 patch
Comment 4 Greg Kroah-Hartman 2005-08-18 21:37:55 UTC 
accepted into the -mm kernel tree and will go into 2.6.14 when it comes out.
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