On Mon, Nov 25, 2013 at 06:33:02PM +0200, Aaro Koskinen wrote:
> Hi,
> 
> On Sun, Nov 24, 2013 at 10:43:59PM +0000, Russell King - ARM Linux wrote:
> > On Mon, Nov 25, 2013 at 12:22:47AM +0200, Aaro Koskinen wrote:
> > > [   33.967324] ohci ohci: Coherent DMA mask 0xffffffff (pfn 
> > > 0xe0000-0xe0000) covers a smaller range of system memory than the DMA 
> > > zone pfn 0x0-0x100000
> > > 
> > > I bisected this to 4dcfa60071b3d23f0181f27d8519f12e37cefbb9 (ARM: DMA-API:
> > > better handing of DMA masks for coherent allocations). Reverting that
> > > commit makes the USB work again fine.
> 
> [...]
> 
> > Better would be:
> > 
> > #define __arch_dma_to_pfn(dev, addr)        \
> >     ({ unsigned long pfn = (addr) >> PAGE_SHIFT;            \
> >        if (is_lbus_device(dev))                             \
> >             pfn += PHYS_PFN_OFFSET -                        \
> >                     (OMAP1510_LB_OFFSET >> PAGE_SHIFT);     \
> >        pfn;                                                 \
> >     })
> > 
> > Can you try that in arch/arm/mach-omap1/include/mach/memory.h please?
> 
> Still doesn't work:
> 
> [   33.878790] ohci ohci: Coherent DMA mask 0xffffffff (pfn 
> 0xfffe0000-0xe0000) covers a smaller range of system memory than the DMA zone 
> pfn 0x0-0x100000
> [   33.894019] ohci ohci: can't setup: -12

Well, that looks technically better, rather unfortunate that we end up
going to negative PFNs though.

Without that change, could you try this instead please:

 arch/arm/mm/dma-mapping.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index f0ea0134e5a3..a18cfc53f445 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -9,6 +9,7 @@
  *
  *  DMA uncached mapping support.
  */
+#include <linux/bootmem.h>
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/gfp.h>
@@ -162,6 +163,8 @@ static u64 get_coherent_dma_mask(struct device *dev)
        u64 mask = (u64)DMA_BIT_MASK(32);
 
        if (dev) {
+               unsigned long max_dma_pfn;
+
                mask = dev->coherent_dma_mask;
 
                /*
@@ -173,6 +176,8 @@ static u64 get_coherent_dma_mask(struct device *dev)
                        return 0;
                }
 
+               max_dma_pfn = min(max_pfn, arm_dma_pfn_limit);
+
                /*
                 * If the mask allows for more memory than we can address,
                 * and we actually have that much memory, then fail the
@@ -180,7 +185,7 @@ static u64 get_coherent_dma_mask(struct device *dev)
                 */
                if (sizeof(mask) != sizeof(dma_addr_t) &&
                    mask > (dma_addr_t)~0 &&
-                   dma_to_pfn(dev, ~0) > arm_dma_pfn_limit) {
+                   dma_to_pfn(dev, ~0) > max_dma_pfn) {
                        dev_warn(dev, "Coherent DMA mask %#llx is larger than 
dma_addr_t allows\n",
                                 mask);
                        dev_warn(dev, "Driver did not use or check the return 
value from dma_set_coherent_mask()?\n");
@@ -192,7 +197,7 @@ static u64 get_coherent_dma_mask(struct device *dev)
                 * fits within the allowable addresses which we can
                 * allocate.
                 */
-               if (dma_to_pfn(dev, mask) < arm_dma_pfn_limit) {
+               if (dma_to_pfn(dev, mask) < max_dma_pfn) {
                        dev_warn(dev, "Coherent DMA mask %#llx (pfn %#lx-%#lx) 
covers a smaller range of system memory than the DMA zone pfn 0x0-%#lx\n",
                                 mask,
                                 dma_to_pfn(dev, 0), dma_to_pfn(dev, mask) + 1,

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