On Tue, May 29, 2012 at 04:50:45PM +0200, Marek Szyprowski wrote:
Hello,
On Tuesday, May 29, 2012 2:30 PM Russell King - ARM Linux wrote:
I notice we have new warnings as a result of CMA being merged, though thankfully they're just in Kconfig:
warning: (ARM) selects CMA which has unmet direct dependencies (HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK && EXPERIMENTAL)
This seems totally weird: you're mandating that ARM must have CMA selected, but it's an experimental feature? So you're implying that the entire ARM kernel becomes totally experimental for the next release cycle?
I think this needs fixing.
No, that wasn't my intention. I will provide a patch which removes unconditional dependency on CMA - it will let one to disable CMA and use old allocation method if needed, but this requires a few more changes in the dma-mapping implementation. I wasn't aware of the consequences and no one has complained about this since v15 of CMA patches (Aug 2011).
I've just been looking at the automatic build and boot logs, and CMA looks like it has the potential to cause regressions:
Linux version 3.4.0+ (rmk@rmk-PC.arm.linux.org.uk) (gcc version 4.3.5 (GCC) ) #1 PREEMPT Fri Jun 1 02:01:58 BST 2012 CPU: ARMv7 Processor [411fc082] revision 2 (ARMv7), cr=10c53c7d CPU: PIPT / VIPT nonaliasing data cache, VIPT nonaliasing instruction cache Machine: OMAP LDP board vmalloc area is too big, limiting to 976MB Reserving 2097152 bytes SDRAM for VRAM cma: CMA: failed to reserve 16 MiB ... Kernel command line: console=ttyO2,115200n8 noinitrd vmalloc=1G mem=128M root=/dev/mmcblk0p2 rw ip=none rootdelay=2 video=omap24xxfb:rotation=270 ... NET: Registered protocol family 16 initlevel:2=postcore, 16 registered initcalls DMA: failed to allocate 256 KiB pool for atomic coherent allocation
I don't see any other failures, but that doesn't look good...
Note that that command line has worked perfectly well up until now.