From: Jiang Liu Date: Wed, 8 Jul 2015 07:41:42 +0000 (+0800) Subject: dmaengine: ioatdma: Ignore IOAT devices under hotplug-capable PCI host bridge X-Git-Tag: omap-for-v4.3/fixes-rc1~94^2~77 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b6c52c634506d52b3a2dc18503980d717e478739;p=pandora-kernel.git dmaengine: ioatdma: Ignore IOAT devices under hotplug-capable PCI host bridge The dmaengine core assumes that async DMA devices will only be removed when they not used anymore, or it assumes dma_async_device_unregister() will only be called by dma driver exit routines. But this assumption is not true for the IOAT driver, which calls dma_async_device_unregister() from ioat_remove(). So current IOAT driver doesn't support device hot-removal because it may cause system crash to hot-remove an inuse IOAT device. To support CPU socket hot-removal, all PCI devices, including IOAT devices embedded in the socket, will be hot-removed. The idea solution is to enhance the dmaengine core and IOAT driver to support hot-removal, but that's too hard. This patch implements a hack to disable IOAT devices under hotplug-capable CPU socket so it won't break socket hot-removal. Signed-off-by: Jiang Liu Signed-off-by: Vinod Koul --- Reading git-diff-tree failed