My ltmodem patch
dnell <[email protected]> Wed, 2 Nov 2011 07:44:31 +0200
| Newsgroups | gmane.linux.linmodem |
|---|---|
| Message-ID | <[email protected]> |
------a8P4fDEW-Nx2KzBI2wtgo5AgI:1320035971 Content-Type: text/plain; charset=US-ASCII Hi to all. Some long time I use Lucent modem and ltmodem-* packages with Linux. In common they work, but... When I had compare the modem performance with Windows, it is significantly better than with Linux. With both systems the modem report nearly same "connection speed" (for example 48000 bits per second), but the resulting speed of (tcp/ip) network transfers with Linux are significantly less (for example, it is about 4 KByte per second (what corresponds 3600 Kbit per second) but usually ever less and about 3KB per second) than with Windows (which are 5 KBytes per second and the better "responsiveness"). I explore the problem and found the cause. It is (for now) in open source v8250 module (but the problem are from long past time). I think, that the driver and the module are really too big, and ever the driver contains some surplus code and data... In short, I correct the v8250.c file and the network performance of my Linux system become significantly better. In common the download speed as reported by the downloader go up about 1.5 times. In other cases, I think as the modem compression take significant effect, the speed go up ever more, about 3 - 4 times. For now, I use Linux 2.6.35 kernel and modified ltmodem-20100102. The patch are here (the most of it are some my comments, which may be yet some errorneous, but... :-) Excuse me). There are one line of real code. ------a8P4fDEW-Nx2KzBI2wtgo5AgI:1320035971 Content-Type: text/plain; name="patch" Content-Disposition: attachment Content-Transfer-Encoding: base64 KioqIGx0bW9kZW0tMjAxMDAxMDIvdjgyNTAuYwlXZWQgRmViICAzIDAzOjA3OjQ4IDIwMTAKLS0t IGx0bW9kZW0tMjAxMDAxMDItcWxtb2RpZi92ODI1MC5jCVN1biBPY3QgMjMgMDE6MDc6MDcgMjAx MQoqKioqKioqKioqKioqKioKKioqIDE4NiwxOTAgKioqKgogICNlbmRpZgogIAl1bnNpZ25lZCBj aGFyIGNoLCBsc3IgPSAqc3RhdHVzOwohIAlpbnQgbWF4X2NvdW50ID0gMjU2OwogIAljaGFyIGZs YWc7CiAgCi0tLSAxODYsMTkwIC0tLS0KICAjZW5kaWYKICAJdW5zaWduZWQgY2hhciBjaCwgbHNy ID0gKnN0YXR1czsKISAJaW50IG1heF9jb3VudCA9IDI1NjsgLyogTWF5IGJlIDUxMiBvciBmaWZv c2l6ZSBhcmUgYmV0dGVyPyAtLSBRTCAqLwogIAljaGFyIGZsYWc7CiAgCioqKioqKioqKioqKioq KgoqKiogMjY4LDI3MiAqKioqCiAgCX0KICAKISAJY291bnQgPSB1cC0+dHhfbG9hZHN6OwogIAlk byB7CiAgCQlzZXJpYWxfb3V0KHVwLCBVQVJUX1RYLCB4bWl0LT5idWZbeG1pdC0+dGFpbF0pOwot LS0gMjY4LDI3MiAtLS0tCiAgCX0KICAKISAJY291bnQgPSB1cC0+dHhfbG9hZHN6OyAvKiBzaW1w bGUgNjQgYnkgc3RyYW5nZSB3YXkuIC0tIFFMICovCiAgCWRvIHsKICAJCXNlcmlhbF9vdXQodXAs IFVBUlRfVFgsIHhtaXQtPmJ1Zlt4bWl0LT50YWlsXSk7CioqKioqKioqKioqKioqKgoqKiogODU4 LDg2MSAqKioqCi0tLSA4NTgsODYyIC0tLS0KICAJCXVhcnQtPnBvcnQuZmxhZ3MgICAgPSB2dWFy dF9jb25maWdbdWFydC0+dnR5cGVdLmZsYWdzIC8qfCBVUEZfQk9PVF9BVVRPQ09ORiovOwogIAkJ dWFydC0+dmZsYWdzCSAgICA9IGNvbmYtPmZsYWdzOworIAkJdWFydC0+dHhfbG9hZHN6ICAgICA9 IHZ1YXJ0X2NvbmZpZ1t1YXJ0LT52dHlwZV0udHhfbG9hZHN6OyAvKiBzaW1wbGUgNjQgYnkgc3Ry YW5nZSB3YXkuIC0tIFFMICovCiAgCiAgCQl1YXJ0LT5ob3N0CSAgICA9IGhvc3Q7CioqKioqKioq KioqKioqKgoqKiogODY0LDg2OCAqKioqCiAgCQkKICAJCXVhcnQtPnBvcnQudHlwZQkgICAgPSBQ T1JUX1ZVQVJUOwohIAkJdWFydC0+cG9ydC5maWZvc2l6ZSA9IHZ1YXJ0X2NvbmZpZ1t1YXJ0LT52 dHlwZV0uZmlmb19zaXplOwogIAogIAkJcmV0ID0gdWFydF9hZGRfb25lX3BvcnQoJnNlcmlhbDgy NTBfcmVnLCAmdWFydC0+cG9ydCk7Ci0tLSA4NjUsODY5IC0tLS0KICAJCQogIAkJdWFydC0+cG9y dC50eXBlCSAgICA9IFBPUlRfVlVBUlQ7CiEgCQl1YXJ0LT5wb3J0LmZpZm9zaXplID0gdnVhcnRf Y29uZmlnW3VhcnQtPnZ0eXBlXS5maWZvX3NpemU7IC8qIHNpbXBsZSA1MTIgYnkgc3RyYW5nZSB3 YXkuIC0tIFFMICovCiAgCiAgCQlyZXQgPSB1YXJ0X2FkZF9vbmVfcG9ydCgmc2VyaWFsODI1MF9y ZWcsICZ1YXJ0LT5wb3J0KTsK ------a8P4fDEW-Nx2KzBI2wtgo5AgI:1320035971--