On Tue, May 11, 2021 at 08:35:47PM +0800, Kefeng Wang wrote: > > > On 2021/3/8 17:58, Greg KH wrote: > > On Mon, Mar 08, 2021 at 11:20:03AM +0800, Jing Xiangfeng wrote: > > > > > > > > > On 2021/3/7 23:24, Greg KH wrote: > > > > On Thu, Mar 04, 2021 at 04:09:28PM +0100, Nicolas Saenz Julienne wrote: > > > > > On Thu, 2021-03-04 at 15:17 +0100, Greg KH wrote: > > > > > > On Thu, Mar 04, 2021 at 03:05:32PM +0100, Nicolas Saenz Julienne wrote: > > > > > > > Hi Greg. > > > > > > > > > > > > > > On Thu, 2021-03-04 at 14:46 +0100, Greg KH wrote: > > > > > > > > On Wed, Mar 03, 2021 at 03:33:12PM +0800, Jing Xiangfeng wrote: > > > > > > > > > Using two distinct DMA zones turned out to be problematic. Here's an > > > > > > > > > attempt go back to a saner default. > > > > > > > > What problem does this solve? How does this fit into the stable kernel > > > > > > > > rules? > > > > > > > We changed the way we setup memory zones in arm64 in order to cater for > > > > > > > Raspberry Pi 4's weird DMA constraints: ZONE_DMA spans the lower 1GB of memory > > > > > > > and ZONE_DMA32 the rest of the 32bit address space. Since you can't allocate > > > > > > > memory that crosses zone boundaries, this broke crashkernel allocations on big > > > > > > > machines. This series fixes all this by parsing the HW description and checking > > > > > > > for DMA constrained buses. When not found, the unnecessary zone creation is > > > > > > > skipped. > > > > > > What kernel/commit caused this "breakage"? > > > > > 1a8e1cef7603 arm64: use both ZONE_DMA and ZONE_DMA32 > > > > Thanks for the info, all now queued up. > > > There is a fix in 5.11. Please consider applying the following commit to > > > 5.10.y: > > > > > > aed5041ef9a3 of: unittest: Fix build on architectures without > > > CONFIG_OF_ADDRES > > > > Thanks, now queued up. > > Hi Grep, another commit d78050ee3544 "arm64: Remove arm64_dma32_phys_limit > and its uses" should be involved, thanks. > > "Prior to this patch, disabling CONFIG_ZONE_DMA32 leads to CMA > allocation from the whole RAM as arm64_dma32_phys_limit becomes > PHYS_MASK+1." from Catalin, see more from the link > https://www.spinics.net/lists/arm-kernel/msg867356.html Ok, now queued up. greg k-h
