From ee41d11d53c8fc4968f0816504651541d606cf40 Mon Sep 17 00:00:00 2001 From: Ian Munsie Date: Mon, 8 Dec 2014 19:17:55 +1100 Subject: cxl: Change contexts_lock to a mutex to fix sleep while atomic bug We had a known sleep while atomic bug if a CXL device was forcefully unbound while it was in use. This could occur as a result of EEH, or manually induced with something like this while the device was in use: echo 0000:01:00.0 > /sys/bus/pci/drivers/cxl-pci/unbind The issue was that in this code path we iterated over each context and forcefully detached it with the contexts_lock spin lock held, however the detach also needed to take the spu_mutex, and call schedule. This patch changes the contexts_lock to a mutex so that we are not in atomic context while doing the detach, thereby avoiding the sleep while atomic. Also delete the related TODO comment, which suggested an alternate solution which turned out to not be workable. Cc: stable@vger.kernel.org Signed-off-by: Ian Munsie Signed-off-by: Michael Ellerman --- drivers/misc/cxl/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/misc/cxl/pci.c') diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c index 10c98ab7f46e..0f2cc9f8b4db 100644 --- a/drivers/misc/cxl/pci.c +++ b/drivers/misc/cxl/pci.c @@ -502,7 +502,7 @@ static struct cxl_afu *cxl_alloc_afu(struct cxl *adapter, int slice) afu->dev.release = cxl_release_afu; afu->slice = slice; idr_init(&afu->contexts_idr); - spin_lock_init(&afu->contexts_lock); + mutex_init(&afu->contexts_lock); spin_lock_init(&afu->afu_cntl_lock); mutex_init(&afu->spa_mutex); -- cgit v1.2.3