On 04/15/2016 02:31 PM, Felipe Balbi wrote:
>
> Hi,
>
> Catalin Marinas <catalin.marinas@xxxxxxx> writes:
>> On Fri, Apr 15, 2016 at 01:30:01PM +0300, Felipe Balbi wrote:
>>> Catalin Marinas <catalin.marinas@xxxxxxx> writes:
>>>> On Fri, Apr 15, 2016 at 11:01:08AM +0100, Catalin Marinas wrote:
>>>>> On Fri, Apr 15, 2016 at 12:49:15PM +0300, Felipe Balbi wrote:
>>>>>> Catalin Marinas <catalin.marinas@xxxxxxx> writes:
>>>>>>> On Thu, Apr 14, 2016 at 12:46:47PM +0000, David Fisher wrote:
>>>>>>>> dwc3 is in dual-role, with "synopsys,dwc3" specified in DT.
>>>>>>>>
>>>>>>>> When xhci is probed, initiated from dwc3/host.c (not DT), we get :
>>>>>>>> xhci-hcd: probe of xhci-hcd.7.auto failed with error -5
>>>>>>>> This -EIO error originated from inside dma_set_mask() down in include/asm-generic/dma-mapping-common.h
>>>>>>>>
>>>>>>>> If "generic-xhci" is specified in DT instead, it probes fine as a host-only dwc3
>>>>>>>> The difference between DT initiated probe and dwc3 initiated probe is that
>>>>>>>> when DT initiated probe gets to dma_supported, dma_supported is
>>>>>>>> implemented by swiotlb_dma_supported (previously set up by a DT call to arch_dma_setup_ops).
>>>>>>>> Whereas when dwc3 initiated xhci probe gets to dma_supported, arch_dma_setup_ops has not been called
>>>>>>>> and dma_supported is only implemented by __dummy_dma_supported, returning 0.
>>>>>>>>
>>>>>>>> Bisecting finds the "bad" commit as
>>>>>>>> 1dccb598df549d892b6450c261da54cdd7af44b4 (inbetween 4.4-rc1 and 4.4-rc2)
>>>>>>>> --- a/arch/arm64/include/asm/dma-mapping.h
>>>>>>>> --- a/arch/arm64/mm/dma-mapping.c
>>>>>>>>
>>>>>>>> Previous to this commit, dma_ops = &swiotlb_dma_ops was done in arm64_dma_init
>>>>>>>> After this commit, the assignment is only done in arch_dma_setup_ops.
>>>>>>>
>>>>>>> This restriction was added on purpose and the arm64 __generic_dma_ops()
>>>>>>> now has a comment:
>>>>>>>
>>>>>>> /*
>>>>>>> * We expect no ISA devices, and all other DMA masters are expected to
>>>>>>> * have someone call arch_setup_dma_ops at device creation time.
>>>>>>> */
>>>>>>
>>>>>> how ?
>>>>>
>>>>> Usually by calling arch_setup_dma_ops().
>>>>
>>>> Or of_dma_configure(), I forgot to mention this (see the
>>>> pci_dma_configure() function as an example).
>>>
>>> the device is manually created, there's not OF/DT for it ;-)
>>
>> As for PCI, the created device doesn't have a node but the bridge does.
>> Something like below, completely untested:
>>
>> diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
>> index c679f63783ae..96d8babd7f23 100644
>> --- a/drivers/usb/dwc3/host.c
>> +++ b/drivers/usb/dwc3/host.c
>> @@ -32,7 +32,10 @@ int dwc3_host_init(struct dwc3 *dwc)
>> return -ENOMEM;
>> }
>>
>> - dma_set_coherent_mask(&xhci->dev, dwc->dev->coherent_dma_mask);
>> + if (IS_ENABLED(CONFIG_OF) && dwc->dev->of_node)
>> + of_dma_configure(&xhci->dev, dwc->dev->of_node);
>> + else
{
>> + dma_set_coherent_mask(&xhci->dev, dwc->dev->coherent_dma_mask);
xhci->dev.dma_mask = dwc->dev->dma_mask;
xhci->dev.dma_parms = dwc->dev->dma_parms;
}
>
> assuming this works fine for all users, I don't have an issue with
> it. Grygorii has just been working on DMA setup for k2 and dwc3, so I
> want to make sure this won't regress those devices.
>
And this is the same approach I've proposed here:
https://lkml.org/lkml/2016/3/31/609
:)
So, final change could be:
---
>From c68225e97e8c9505aca4ceab19a0d8e4dde31b73 Mon Sep 17 00:00:00 2001
From: Grygorii Strashko <grygorii.strashko@xxxxxx>
Date: Thu, 31 Mar 2016 19:40:52 +0300
Subject: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev
Now not all DMA paremters configured properly for "xhci-hcd" platform
device which is created manually. For example: dma_pfn_offset, dam_ops
and iommu configuration will not corresponds "dwc3" devices
configuration. As result, this will cause problems like wrong DMA
addresses translation on platforms with LPAE enabled like Keystone 2.
When platform is using DT boot mode the DMA configuration will be
parsed and applied from DT, so, to fix this issue, reuse
of_dma_configure() API and retrieve DMA configuartion for "xhci-hcd"
from DWC3 device node.
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
---
drivers/usb/dwc3/host.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/dwc3/host.c b/drivers/usb/dwc3/host.c
index c679f63..93c8ef9 100644
--- a/drivers/usb/dwc3/host.c
+++ b/drivers/usb/dwc3/host.c
@@ -17,6 +17,7 @@
#include <linux/platform_device.h>
#include <linux/usb/xhci_pdriver.h>
+#include <linux/of_device.h>
#include "core.h"
@@ -32,12 +33,7 @@ int dwc3_host_init(struct dwc3 *dwc)
return -ENOMEM;
}
- dma_set_coherent_mask(&xhci->dev, dwc->dev->coherent_dma_mask);
-
xhci->dev.parent = dwc->dev;
- xhci->dev.dma_mask = dwc->dev->dma_mask;
- xhci->dev.dma_parms = dwc->dev->dma_parms;
-
dwc->xhci = xhci;
ret = platform_device_add_resources(xhci, dwc->xhci_resources,
@@ -62,6 +58,15 @@ int dwc3_host_init(struct dwc3 *dwc)
phy_create_lookup(dwc->usb3_generic_phy, "usb3-phy",
dev_name(&xhci->dev));
+ if (IS_ENABLED(CONFIG_OF) && dwc->dev->of_node) {
+ of_dma_configure(&xhci->dev, dwc->dev->of_node);
+ } else {
+ dma_set_coherent_mask(&xhci->dev, dwc->dev->coherent_dma_mask);
+
+ xhci->dev.dma_mask = dwc->dev->dma_mask;
+ xhci->dev.dma_parms = dwc->dev->dma_parms;
+ }
+
ret = platform_device_add(xhci);
if (ret) {
dev_err(dwc->dev, "failed to register xHCI device\n");
--
2.8.1
--
regards,
-grygorii
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