https://github.com/torvalds/linux
Revision d84248bf46582a406116c55b94405c05193773b1 authored by Rini van Zetten on 10 December 2007, 23:49:34 UTC, committed by Linus Torvalds on 11 December 2007, 03:43:55 UTC
We have a wifi module connected to the spi bus and got sometimes FIFO
overrun errors on the spi bus.

After some investigation i found that the driver loads the TCR (transmit
count) register before the RCR (receive count).  When the transfer list is
not empty the atmel_spi_next_message is called while tx and rx are enabled.
 As soon as the TCR is loaded, hardware starts transfer and causes a rx
fifo overrun because the RCR is not loaded yet.

Load the RCR before the TCR.  After this patch the fifo overrun disapears
at out setup.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Rini van Zetten <rini@arvoo.nl>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 6650e0a
History
Tip revision: d84248bf46582a406116c55b94405c05193773b1 authored by Rini van Zetten on 10 December 2007, 23:49:34 UTC
atmel_spi: reload RCR before TCR
Tip revision: d84248b
File Mode Size
Documentation
arch
block
crypto
drivers
fs
include
init
ipc
kernel
lib
mm
net
samples
scripts
security
sound
usr
.gitignore -rw-r--r-- 628 bytes
.mailmap -rw-r--r-- 3.6 KB
COPYING -rw-r--r-- 18.3 KB
CREDITS -rw-r--r-- 90.1 KB
Kbuild -rw-r--r-- 1.6 KB
MAINTAINERS -rw-r--r-- 91.3 KB
Makefile -rw-r--r-- 51.9 KB
README -rw-r--r-- 16.5 KB
REPORTING-BUGS -rw-r--r-- 3.0 KB

README

back to top