On 02/06/2015 10:12 AM, Catalin Marinas wrote:
On Fri, Feb 06, 2015 at 02:54:23PM +0000, Murali Karicheri wrote:
On 02/06/2015 09:38 AM, Catalin Marinas wrote:
On Thu, Feb 05, 2015 at 09:52:55PM +0000, Murali Karicheri wrote:
Fix the dma-range size when the DT attribute is missing. i.e set size to
dev->coherent_dma_mask + 1 instead of dev->coherent_dma_mask. Also add
code to check invalid values of size configured in DT and log error.
Cc: Joerg Roedel<joro@xxxxxxxxxx>
Cc: Grant Likely<grant.likely@xxxxxxxxxx>
Cc: Rob Herring<robh+dt@xxxxxxxxxx>
Cc: Bjorn Helgaas<bhelgaas@xxxxxxxxxx>
Cc: Will Deacon<will.deacon@xxxxxxx>
Cc: Russell King<linux@xxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann<arnd@xxxxxxxx>
Cc: Suravee Suthikulpanit<Suravee.Suthikulpanit@xxxxxxx>
Signed-off-by: Murali Karicheri<m-karicheri2@xxxxxx>
---
drivers/of/device.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 2de320d..314c8a9 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -105,9 +105,24 @@ void of_dma_configure(struct device *dev, struct device_node *np)
ret = of_dma_get_range(np,&dma_addr,&paddr,&size);
if (ret< 0) {
dma_addr = offset = 0;
- size = dev->coherent_dma_mask;
+ size = dev->coherent_dma_mask + 1;
} else {
offset = PFN_DOWN(paddr - dma_addr);
+
+ /*
+ * Add a work around to treat the size as mask + 1 in case
+ * it is defined in DT as a mask.
+ */
+ if (size& 1) {
+ dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
+ size);
+ size = size + 1;
+ }
+
+ if (!size) {
+ dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
+ return;
+ }
Would it make sense to set coherent_dma_mask to 0 here to make this more
noticeable? It can be done together with the mask calculation from size.
I guess you are the following in the code.
if (!size) {
dev->coherent_dma_mask = 0;
dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
return;
}
Not sure how this is going to help and how this get handled by the
caller and subsequent logic. Probably it will cause probe to fail, with
some helpful error code.
Not sure how it will fail, maybe the driver figures out that DMA isn't
available and say something or switch to PIO. I guess you can leave it
as 32-bit mask by default for now even in case of size == 0.
BTW, since pci_device_add() already sets coherent_dma_mask, you could
add another check at the beginning of of_dma_configure():
if (!dev->coherent_dma_mask)
dev->coherent_dma_mask = DMA_BIT_MASK(32);
That's more of a nitpick as the values are both the same.
Catalin,
Just posted a patch for size based dma mask with title "of: calculate
masks of the device based on dma-range size". Please review and comment
--
Murali Karicheri
Linux Kernel, Texas Instruments
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