Implement the suggested workaround for OMAP3 regarding to sDMA draining
issue, when the channel is disabled on the fly.
This errata affects the following configuration:
sDMA transfer is source synchronized
Buffering is enabled
SmartStandby is selected.
The issue can be easily reproduced by creating overrun situation while
recording audio.
Either introduce load to the CPU:
nice -19 arecord -D hw:0 -M -B 10000 -F 5000 -f dat > /dev/null & \
dd if=/dev/urandom of=/dev/null
or suspending the arecord, and resuming it:
arecord -D hw:0 -M -B 10000 -F 5000 -f dat > /dev/null
CTRL+Z; fg; CTRL+Z; fg; ...
In case of overrun audio stops DMA, and restarts it (without reseting
the sDMA channel). When we hit this errata in stop case (sDMA drain did
not complete), at the coming start the sDMA will not going to be
operational (it is still draining).
This leads to DMA stall condition.
On OMAP3 we can recover with sDMA channel reset, it has been observed
that by introducing unrelated sDMA activity might also help (reading
from MMC for example).
The same errata exists for OMAP2, where the suggestion is to disable the
buffering to avoid this type of error.
On OMAP3 the suggestion is to set sDMA to NoStandby before disabling
the channel, and wait for the drain to finish, than configure sDMA to
SmartStandby again.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Jarkko Nikula <jhnikula@gmail.com>
Acked-by : Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by : Manjunath Kondaiah G <manjugk@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
An errata workaround for omap24xx is not setting the buffering disable bit
25 what is the purpose but channel enable bit 7 instead.
Background for this fix is the DMA stalling issue with ASoC omap-mcbsp
driver. Peter Ujfalusi <peter.ujfalusi@nokia.com> has found an issue in
recording that the DMA stall could happen if there were a buffer overrun
detected by ALSA and the DMA was stopped and restarted due that. This
problem is known to occur on both OMAP2420 and OMAP3. It can recover on
OMAP3 after dma free, dma request and reconfiguration cycle. However, on
OMAP2420 it seems that only way to recover is a reset.
Problem was not visible before the commit c12abc0. That commit changed that
the McBSP transmitter/receiver is released from reset only when needed. That
is, only enabled McBSP transmitter without transmission was able to prevent
this DMA stall problem in receiving side and underlying problem did not show
up until now. McBSP transmitter itself seems to no be reason since DMA
stall does not recover by enabling the transmission after stall.
Debugging showed that there were a DMA write active during DMA stop time and
it never completed even when restarting the DMA. Experimenting showed that
the DMA buffering disable bit could be used to avoid stalling when using
source synchronized transfers. However that could have performance hit and
OMAP3 TRM states that buffering disable is not allowed for destination
synchronized transfers so subsequent patch will implement a method to
complete DMA writes when stopping.
This patch is based on assumtion that complete lock-up on OMAP2420 is
different but related problem. I don't have access to OMAP2420 errata but
I believe this old workaround here is put for a reason but unfortunately
a wrong bit was typed and problem showed up only now.
Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Acked-by: Manjunath Kondaiah G <manjugk@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This patch adds omap_hwmod data for UARTs on OMAP2 and OMAP3
platforms.
UART4 support for 3630 and OMAP2 hwmod data added by Govindraj R.
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Omap DMA controller can prefetch data in advance in case of
destination synchronized data transfer. This may increase
performance when target HW block doesn't have fifo.
Data is waiting for transfer request in DMA fifo instead of read from memory.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
This patch removes all the omap4 specific dma request
lines defines from plat/dma.h and includes dma-44xx.h
The defines are aligned so no driver should be impacted
because of this change.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@deeprootsystems.com>
Reviewed-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
All of the LCD DMA code in plat-omap/dma.c appears to be OMAP1-only (and
apparently only is available on a subset of OMAP1 chips).
Move this code to mach-omap1/lcd_dma.c.
Tested on OMAP1510 Amstrad Delta.
Compile-tested with omap_generic_2420_defconfig.
Reported-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Reviewed-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
For HS/EMU devices, these additional features are also used:
- DMA interrupt disable routine added
- Added DMA controller reset to DMA context restore
Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Move the remaining headers under plat-omap/include/mach
to plat-omap/include/plat. Also search and replace the
files using these headers to include using the right path.
This was done with:
#!/bin/bash
mach_dir_old="arch/arm/plat-omap/include/mach"
plat_dir_new="arch/arm/plat-omap/include/plat"
headers=$(cd $mach_dir_old && ls *.h)
omap_dirs="arch/arm/*omap*/ \
drivers/video/omap \
sound/soc/omap"
other_files="drivers/leds/leds-ams-delta.c \
drivers/mfd/menelaus.c \
drivers/mfd/twl4030-core.c \
drivers/mtd/nand/ams-delta.c"
for header in $headers; do
old="#include <mach\/$header"
new="#include <plat\/$header"
for dir in $omap_dirs; do
find $dir -type f -name \*.[chS] | \
xargs sed -i "s/$old/$new/"
done
find drivers/ -type f -name \*omap*.[chS] | \
xargs sed -i "s/$old/$new/"
for file in $other_files; do
sed -i "s/$old/$new/" $file
done
done
for header in $(ls $mach_dir_old/*.h); do
git mv $header $plat_dir_new/
done
Signed-off-by: Tony Lindgren <tony@atomide.com>
2009-10-20 09:40:47 -07:00
Renamed from arch/arm/plat-omap/include/mach/dma.h (Browse further)
