commit 58f2266f4019b9d023979de31950d34cce23b43c
author Geert Uytterhoeven <geert@linux-m68k.org> Tue Feb 16 16:10:57 2016 +0100
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> Sat Feb 20 20:22:55 2016 -0800
tree 0eb8d890ab2985385f5eba7ea21759b54b043503
parent ef976ea33b4c44d6cd14ee63cb237c6bab40f91b

usb: core: Allow compilation on platforms where NO_DMA=y

Some platforms don't have DMA, but we should still be able to build USB
drivers for these platforms. They could still be used through vhci_hcd,
usbip_host, or maybe something like USB passthrough in UML from a
capable host.

If NO_DMA=y:

    ERROR: "dma_pool_destroy" [drivers/usb/core/usbcore.ko] undefined!
    ERROR: "bad_dma_ops" [drivers/usb/core/usbcore.ko] undefined!
    ERROR: "dma_pool_free" [drivers/usb/core/usbcore.ko] undefined!
    ERROR: "dma_pool_alloc" [drivers/usb/core/usbcore.ko] undefined!
    ERROR: "dma_pool_create" [drivers/usb/core/usbcore.ko] undefined!

Add a few checks for CONFIG_HAS_DMA to fix this.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/buffer.c

diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index 89f2e77..2741566 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -62,8 +62,9 @@
 	char		name[16];
 	int		i, size;
 
-	if (!hcd->self.controller->dma_mask &&
-	    !(hcd->driver->flags & HCD_LOCAL_MEM))
+	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
+	    (!hcd->self.controller->dma_mask &&
+	     !(hcd->driver->flags & HCD_LOCAL_MEM)))
 		return 0;
 
 	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
@@ -93,6 +94,9 @@
 {
 	int i;
 
+	if (!IS_ENABLED(CONFIG_HAS_DMA))
+		return;
+
 	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
 		struct dma_pool *pool = hcd->pool[i];
 
@@ -119,8 +123,9 @@
 	int			i;
 
 	/* some USB hosts just use PIO */
-	if (!bus->controller->dma_mask &&
-	    !(hcd->driver->flags & HCD_LOCAL_MEM)) {
+	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
+	    (!bus->controller->dma_mask &&
+	     !(hcd->driver->flags & HCD_LOCAL_MEM))) {
 		*dma = ~(dma_addr_t) 0;
 		return kmalloc(size, mem_flags);
 	}
@@ -145,8 +150,9 @@
 	if (!addr)
 		return;
 
-	if (!bus->controller->dma_mask &&
-	    !(hcd->driver->flags & HCD_LOCAL_MEM)) {
+	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
+	    (!bus->controller->dma_mask &&
+	     !(hcd->driver->flags & HCD_LOCAL_MEM))) {
 		kfree(addr);
 		return;
 	}