Messages in this thread | | | Date | Fri, 7 Aug 2009 11:14:57 +0200 | From | Matthieu CASTET <> | Subject | Re: [UBI UBIFS] replace vmalloc with kmalloc |
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JiSheng Zhang a écrit : > If nandflash driver use DMA to support UBI and UBIFS i/o, there will > be panic like > the following. This is because UBI and UBIFS use vmalloced buffer > somewhere while > nandflash driver put the buffer under DMA and DMA support doesn't like vmalloced > memory. > [ 412.369280] UBIFS: default file-system created > [ 412.374879] Unable to handle kernel NULL pointer dereference at > virtual address 00000000 > [ 412.383177] UBIFS: background thread "ubifs_bgt0_0" started, PID 887 > [ 412.389656] pgd = c0004000 > [ 412.392419] [00000000] *pgd=00000000 > [ 412.396117] Internal error: Oops: 817 [#1] PREEMPT > > Yes, I know kmalloc may fail when memory get fragmented, but I grep the UBI and > UBIFS's source, there are six .c files and seven .c files using > vmalloc, the function > which call vmalloc are all called during the ubi being attached and > the volume being > mounted. In embedded system, this mainly happen during kernel boot, it > should succeed. > > After replacing vmalloc with kmalloc, ubi and ubifs runs fine on my > board. I can alos upload > a patch. > > Comments are welcomed! > mtd is not DMA safe. So patching UBI and UBIFS is not enought.
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