* Re: [PATCH] of/irq: fix bug in computing output requester-id for an msi-map
2016-02-08 22:30 [PATCH] of/irq: fix bug in computing output requester-id for an msi-map Stuart Yoder
@ 2016-02-08 23:47 ` David Daney
0 siblings, 0 replies; 2+ messages in thread
From: David Daney @ 2016-02-08 23:47 UTC (permalink / raw)
To: Stuart Yoder
Cc: robh, frowand.list, grant.likely, devicetree, linux-kernel,
marc.zyngier, david.daney, mark.rutland
On 02/08/2016 02:30 PM, Stuart Yoder wrote:
> From: Stuart Yoder <stuart.yoder@nxp.com>
>
> The binding for msi-map specifies that the output requester id
> should be computed as: (r - rid-base + msi-base)
>
> ...update the code accordingly.
I agree there is a problem however ...
>
> Signed-off-by: Stuart Yoder <stuart.yoder@nxp.com>
> ---
> drivers/of/irq.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/irq.c b/drivers/of/irq.c
> index 706e3ff..3f5e5fd 100644
> --- a/drivers/of/irq.c
> +++ b/drivers/of/irq.c
> @@ -589,6 +589,7 @@ static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
> struct device_node *msi_controller_node;
> struct device_node *msi_np = *np;
> u32 map_mask, masked_rid, rid_base, msi_base, rid_len, phandle;
> + u32 masked_rid_base;
> int msi_map_len;
> bool matched;
> u32 rid_out = rid_in;
> @@ -654,7 +655,8 @@ static u32 __of_msi_map_rid(struct device *dev, struct device_node **np,
> if (!matched)
> return rid_out;
>
> - rid_out = masked_rid + msi_base;
> + masked_rid_base = map_mask & rid_base;
... The binding document nowhere, that I see, talks about applying the
mask to the rid-base.
The device tree should already contain the rid-base in the correct range.
If you remove this masking step, I think it may be correct.
If you just do:
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 7ee21ae..92abe01 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -654,7 +654,7 @@ static u32 __of_msi_map_rid(struct device *dev,
struct device_node **np,
if (!matched)
return rid_out;
- rid_out = masked_rid + msi_base;
+ rid_out = msi_base + (masked_rid - rid_base);
dev_dbg(dev,
"msi-map at: %s, using mask %08x, rid-base: %08x,
msi-base: %08x, length: %08x, rid: %08x -> %08x\n",
It think it will be correct.
I have tested it that way. If you do that,
Acked-by: David Daney <david.daney@cavium.com>
> + rid_out = msi_base + (masked_rid - masked_rid_base);
> dev_dbg(dev,
> "msi-map at: %s, using mask %08x, rid-base: %08x, msi-base: %08x, length: %08x, rid: %08x -> %08x\n",
> dev_name(parent_dev), map_mask, rid_base, msi_base,
>
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