xhci: fix dma mask setup in xhci.c
The function dma_set_mask() tests internally whether the dma_mask pointer
for the device is initialized and fails if the dma_mask pointer is NULL.
On pci platforms, the device dma_mask pointer is initialized, when pci
devices are enumerated, to point to the pci_dev->dma_mask which is 0xffffffff.
However, for non-pci platforms, the dma_mask pointer may not be initialized
and in that case dma_set_mask() will fail.
This patch initializes the dma_mask and the coherent_dma_mask to 32bits
in xhci_plat_probe(), before the call to usb_create_hcd() that sets the
"uses_dma" flag for the usb bus and the call to usb_add_hcd() that creates
coherent dma pools for the usb hcd.
Moreover, a call to dma_set_mask() does not set the device coherent_dma_mask.
Since the xhci-hcd driver calls dma_alloc_coherent() and dma_pool_alloc()
to allocate consistent DMA memory blocks, the coherent DMA address mask
has to be set explicitly.
This patch sets the coherent_dma_mask to 64bits in xhci_gen_setup() when
the xHC is capable for 64-bit DMA addressing.
If dma_set_mask() succeeds, for a given bitmask, it is guaranteed that
the given bitmask is also supported for consistent DMA mappings.
Other changes introduced in this patch are:
- The return value of dma_set_mask() is checked to ensure that the required
dma bitmask conforms with the host system's addressing capabilities.
- The dma_mask setup code for the non-primary hcd was removed since both
primary and non-primary hcd refer to the same generic device whose
dma_mask and coherent_dma_mask are already set during the setup of
the primary hcd.
- The code for reading the HCCPARAMS register to find out the addressing
capabilities of xHC was removed since its value is already cached in
xhci->hccparams.
- hcd->self.controller was replaced with the dev variable since it is
already available.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
index 3fcdaea..be5e70d 100644
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -15,6 +15,7 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/of.h>
+#include <linux/dma-mapping.h>
#include "xhci.h"
@@ -105,6 +106,15 @@
if (!res)
return -ENODEV;
+ /* Initialize dma_mask and coherent_dma_mask to 32-bits */
+ ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
+ if (ret)
+ return ret;
+ if (!pdev->dev.dma_mask)
+ pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+ else
+ dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+
hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev));
if (!hcd)
return -ENOMEM;