Software I2C were using a very conservative value of udelay=16, meaning about
20Kbps. According with Philips I2C datasheet, the i2c should answer well for
times at the order of 4.7 us. So, using udelay=5 should work for all devices.
After this patch, the speed should be close to 66,67 Kbps, with the current
kernel software bitbang, with 30/60 duty cycle.
Anyway, added a new parameter (i2c_udelay) that would allow using conservative
values, if eventually a hardware doesn't support the datasheet values.
Thanks to Jean Delvare <khali@linux-fr.org> for pointing this improvement.
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
no_overlay bttv parameter implemented to fix OOPS on some PCI chipsets
(like some VIA) with these behaviors:
1) If pci_quicks does identify the chip as having troubles to
handle PCI2PCI transfers, no_overlay defaults to 1. The user may force
it to 0, to reenable (not recommended).
2) For newer chipsets not blacklisted, no_overlay=1 is provided as a
workaround until PCI chipset included on /drivers/pci/quirks.c
Thanks to Bodo Eggert <7eggert@gmx.de>
Signed-off-by: Michael Krufky <mkrufky@m1k.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!