[SCSI] fix oops in all legacy host adapters caused by 6f381fa

Commit 6f381fa344911d5a234b13574433cf23036f9467
Author: Lin Ming <ming.m.lin@intel.com>

[SCSI] scsi_lib: use correct DMA device in __scsi_alloc_queue
 
Caused a regression where we oops in every legacy mode SCSI host driver
because they supply a NULL pointer to scsi_add_host().  Fix this by checking
for the NULL in scsi_add_host_with_dma() and changing the DMA device to being
the platform_bus in that case (which replicates the original behaviour).

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 351dc0b86fab..a3a056a9db67 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -218,6 +218,9 @@ int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
 
         if (!shost->shost_gendev.parent)
                 shost->shost_gendev.parent = dev ? dev : &platform_bus;
+        if (!dma_dev)
+                dma_dev = shost->shost_gendev.parent;
+
         shost->dma_dev = dma_dev;
 
         error = device_add(&shost->shost_gendev);