[Please CC me, I'm not subscribed]
Some days ago I have wrote to this list to expose a problem I have using
kernel 2.6.0-textX + stv680 + UHCI_HCD driver...
the subject was: "USB-Problems with uhci_hcd + V4L + stv680 driver"
http://marc.theaimsgroup.com/?l=linux-usb-devel&m=106493648430605&w=2
Short summary of previous message:
- using a software like camorama the video stops after some seconds
- then, unplugging/replugging the web-cam, I get a message like:
Unable to handle kernel NULL pointer dereference at virtual...
NEW QUESTIONS
Using 2.4.x kernel I can use two drivers:
1) USB-UHCI: works fine / very slow (~3 fps)
2) UHCI alternate driver: stops working after some seconds / fast (~10 fps)
the only difference with 2.6.x is that here I get a Kernel Panic
(unplugging/replugging)
( for full info on the 2.4.x Kernel Panic look here:
http://www.ussg.iu.edu/hypermail/linux/kernel/0308.1/1295.html )
The only host controller driver that seems to work fine is the "slow" USB-UHCI
of 2.4.x kernels...
Doing a few changes to this driver I be able to improve the performace (fps I
get with camorama: From 3 To 10 fps).
These are the changes (suggested on http://stv0680-usb.sourceforge.net):
___________________________________________________________________________
--- drivers/usb/host/usb-uhci.c.old 2003-10-09 16:18:57.000000000 +0200
+++ drivers/usb/host/usb-uhci.c 2003-10-09 16:20:49.000000000 +0200
@@ -97,7 +97,7 @@
* is optimal, but PCI can be slowed down up-to 5 times, slowing down
* system performance (eg. framebuffer devices).
*/
-#define CONFIG_USB_UHCI_HIGH_BANDWIDTH
+#undef CONFIG_USB_UHCI_HIGH_BANDWIDTH
/* *_DEPTH_FIRST puts descriptor in depth-first mode. This has
* somehow similar effect to FSBR (higher speed), but does not
@@ -105,8 +105,8 @@
* in FSBR case and single device could hog whole USB, starving
* other devices.
*/
-#define USE_CTRL_DEPTH_FIRST 0 // 0: Breadth first, 1: Depth first
-#define USE_BULK_DEPTH_FIRST 0 // 0: Breadth first, 1: Depth first
+#define USE_CTRL_DEPTH_FIRST 1 // 0: Breadth first, 1: Depth first
+#define USE_BULK_DEPTH_FIRST 1 // 0: Breadth first, 1: Depth first
/* Turning off both CONFIG_USB_UHCI_HIGH_BANDWITH and *_DEPTH_FIRST
* will lead to <64KB/sec performance over USB for bulk transfers targeting
___________________________________________________________________________
I don't understand why a driver (like stv680) works better with some specific
parameters and other don't...
I don't understand why 2.6.x has only one UHCI driver (derived from UHCI
alternate driver of 2.4.x) that is the driver that doesn't work for me ;-).
I think "2.4.x UHCI alternate driver" && "2.6.x UHCI-HCD" have some problems
on my hardware (my chipset is VIA KT133 on Asus motherboard).
Full info on my hardware / software have been posted to this list on my
previous message:
http://marc.theaimsgroup.com/?l=linux-usb-devel&m=106493648430605&w=2
BYE
--
Paolo Ornati
Linux v2.4.22
-------------------------------------------------------
This SF.net email is sponsored by: SF.net Giveback Program.
SourceForge.net hosts over 70,000 Open Source Projects.
See the people who have HELPED US provide better services:
Click here: http://sourceforge.net/supporters.php
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
