mirror of
https://github.com/archlinuxarm/PKGBUILDs.git
synced 2024-09-19 22:08:32 +00:00
75 lines
3.1 KiB
Diff
75 lines
3.1 KiB
Diff
From cdd0029a79eefc562e85b6f47074044f637d679c Mon Sep 17 00:00:00 2001
|
|
From: Robin Murphy <robin.murphy@arm.com>
|
|
Date: Fri, 11 Aug 2017 17:29:56 +0100
|
|
Subject: [PATCH 5/5] of: Fix DMA mask generation
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
Historically, DMA masks have suffered some ambiguity between whether
|
|
they represent the range of physical memory a device can access, or the
|
|
address bits a device is capable of driving, particularly since on many
|
|
platforms the two are equivalent. Whilst there are some stragglers left
|
|
(dma_max_pfn(), I'm looking at you...), the majority of DMA code has
|
|
been cleaned up to follow the latter definition, not least since it is
|
|
the only one which makes sense once IOMMUs are involved.
|
|
|
|
In this respect, of_dma_configure() has always done the wrong thing in
|
|
how it generates initial masks based on "dma-ranges". Although rounding
|
|
down did not affect the TI Keystone platform where dma_addr + size is
|
|
already a power of two, in any other case it results in a mask which is
|
|
at best unnecessarily constrained and at worst unusable.
|
|
|
|
BCM2837 illustrates the problem nicely, where we have a DMA base of 3GB
|
|
and a size of 1GB - 16MB, giving dma_addr + size = 0xff000000 and a
|
|
resultant mask of 0x7fffffff, which is then insufficient to even cover
|
|
the necessary offset, effectively making all DMA addresses out-of-range.
|
|
This has been hidden until now (mostly because we don't yet prevent
|
|
drivers from simply overwriting this initial mask later upon probe), but
|
|
due to recent changes elsewhere now shows up as USB being broken on
|
|
Raspberry Pi 3.
|
|
|
|
Make it right by rounding up instead of down, such that the mask
|
|
correctly correctly describes all possisble bits the device needs to
|
|
emit.
|
|
|
|
Fixes: 9a6d7298b083 ("of: Calculate device DMA masks based on DT dma-range size")
|
|
Reported-by: Stefan Wahren <stefan.wahren@i2se.com>
|
|
Reported-by: Andreas Färber <afaerber@suse.de>
|
|
Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
|
|
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
|
|
Acked-by: Rob Herring <robh@kernel.org>
|
|
---
|
|
drivers/of/device.c | 8 ++++----
|
|
1 file changed, 4 insertions(+), 4 deletions(-)
|
|
|
|
diff --git a/drivers/of/device.c b/drivers/of/device.c
|
|
index 28c38c756f92..e0a28ea341fe 100644
|
|
--- a/drivers/of/device.c
|
|
+++ b/drivers/of/device.c
|
|
@@ -89,6 +89,7 @@ int of_dma_configure(struct device *dev, struct device_node *np)
|
|
bool coherent;
|
|
unsigned long offset;
|
|
const struct iommu_ops *iommu;
|
|
+ u64 mask;
|
|
|
|
/*
|
|
* Set default coherent_dma_mask to 32 bit. Drivers are expected to
|
|
@@ -134,10 +135,9 @@ int of_dma_configure(struct device *dev, struct device_node *np)
|
|
* Limit coherent and dma mask based on size and default mask
|
|
* set by the driver.
|
|
*/
|
|
- dev->coherent_dma_mask = min(dev->coherent_dma_mask,
|
|
- DMA_BIT_MASK(ilog2(dma_addr + size)));
|
|
- *dev->dma_mask = min((*dev->dma_mask),
|
|
- DMA_BIT_MASK(ilog2(dma_addr + size)));
|
|
+ mask = DMA_BIT_MASK(ilog2(dma_addr + size - 1) + 1);
|
|
+ dev->coherent_dma_mask &= mask;
|
|
+ *dev->dma_mask &= mask;
|
|
|
|
coherent = of_dma_is_coherent(np);
|
|
dev_dbg(dev, "device is%sdma coherent\n",
|
|
--
|
|
2.14.1
|
|
|