Hi Lauretniu,

> I think that any recent kernel will do, so I'd say your current branch 
> should be fine.

The kernel oopses with "unable to handle kernel paging request at virtual
address 000aba0b" in hcd_alloc_coherent via usb_hcd_map_urb_for_dma. This
relates to patch 2/3 that I didn't quite understand, where

-       retval = dma_declare_coherent_memory(dev, mem->start,
-                                        mem->start - mem->parent->start,
-                                        resource_size(mem));

becomes

+       retval = gen_pool_add_virt(hcd->localmem_pool,
+                                  (unsigned long)mem->start -
+                                       mem->parent->start,
+                                  mem->start, resource_size(mem),

so that arguments two and three switch places. Given

int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
                                dma_addr_t device_addr, size_t size);

and

int gen_pool_add_virt(struct gen_pool *pool, unsigned long virt, phys_addr_t 
phys
                 size_t size, int nid)

it seems that the device address (dma_addr_t device_addr) now becomes a
virtual address (unsigned long virt). Is that intended?

My corresponding patch is below for reference. I applied your 1/3 patch
to test it.

Fredrik

diff --git a/drivers/usb/host/ohci-ps2.c b/drivers/usb/host/ohci-ps2.c
--- a/drivers/usb/host/ohci-ps2.c
+++ b/drivers/usb/host/ohci-ps2.c
@@ -7,6 +7,7 @@
  */
 
 #include <linux/dma-mapping.h>
+#include <linux/genalloc.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/usb.h>
@@ -92,12 +93,12 @@ static irqreturn_t ohci_ps2_irq(struct usb_hcd *hcd)
        return ohci_irq(hcd); /* Call normal IRQ handler. */
 }
 
-static int iopheap_alloc_coherent(struct platform_device *pdev,
-       size_t size, int flags)
+static int iopheap_alloc_coherent(struct platform_device *pdev, size_t size)
 {
        struct device *dev = &pdev->dev;
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct ps2_hcd *ps2priv = hcd_to_priv(hcd);
+       int err;
 
        if (ps2priv->iop_dma_addr != 0)
                return 0;
@@ -112,28 +113,37 @@ static int iopheap_alloc_coherent(struct platform_device 
*pdev,
                return -ENOMEM;
        }
 
-       if (dma_declare_coherent_memory(dev,
-                       iop_bus_to_phys(ps2priv->iop_dma_addr),
-                       ps2priv->iop_dma_addr, size, flags)) {
-               dev_err(dev, "dma_declare_coherent_memory failed\n");
-               iop_free(ps2priv->iop_dma_addr);
-               ps2priv->iop_dma_addr = 0;
-               return -ENOMEM;
+       hcd->localmem_pool = devm_gen_pool_create(dev,
+               PAGE_SHIFT, dev_to_node(dev), DRV_NAME);
+       if (IS_ERR(hcd->localmem_pool)) {
+               err = PTR_ERR(hcd->localmem_pool);
+               goto out_err;
+       }
+
+       err = gen_pool_add_virt(hcd->localmem_pool, ps2priv->iop_dma_addr,
+               iop_bus_to_phys(ps2priv->iop_dma_addr), size, dev_to_node(dev));
+       if (err < 0) {
+               dev_err(dev, "gen_pool_add_virt failed with %d\n", err);
+               goto out_err;
        }
 
        return 0;
+
+out_err:
+       iop_free(ps2priv->iop_dma_addr);
+       ps2priv->iop_dma_addr = 0;
+
+       return err;
 }
 
 static void iopheap_free_coherent(struct platform_device *pdev)
 {
-       struct device *dev = &pdev->dev;
        struct usb_hcd *hcd = platform_get_drvdata(pdev);
        struct ps2_hcd *ps2priv = hcd_to_priv(hcd);
 
        if (ps2priv->iop_dma_addr == 0)
                return;
 
-       dma_release_declared_memory(dev);
        iop_free(ps2priv->iop_dma_addr);
        ps2priv->iop_dma_addr = 0;
 }
@@ -177,8 +187,7 @@ static int ohci_hcd_ps2_probe(struct platform_device *pdev)
                goto err;
        }
 
-       ret = iopheap_alloc_coherent(pdev,
-               DMA_BUFFER_SIZE, DMA_MEMORY_EXCLUSIVE);
+       ret = iopheap_alloc_coherent(pdev, DMA_BUFFER_SIZE);
        if (ret != 0)
                goto err_alloc_coherent;
 

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