From: David Daney Subject: Re: [PATCH] of/irq: fix bug in computing output requester-id for an msi-map Date: Mon, 8 Feb 2016 15:47:04 -0800 Message-ID: <56B928F8.3010104@caviumnetworks.com> References: <1454970623-28781-1-git-send-email-stuart.yoder@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1454970623-28781-1-git-send-email-stuart.yoder@nxp.com> Sender: linux-kernel-owner@vger.kernel.org To: Stuart Yoder Cc: robh@kernel.org, frowand.list@gmail.com, grant.likely@linaro.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, marc.zyngier@arm.com, david.daney@cavium.com, mark.rutland@arm.com List-Id: devicetree@vger.kernel.org On 02/08/2016 02:30 PM, Stuart Yoder wrote: > From: Stuart Yoder > > 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 > --- > 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 > + 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, >