diff mbox

trouble with PCI: Call pci_read_bridge_bases() from core instead of arch code

Message ID CAE9FiQWUr6f_KsTyJrntRg-uuF1OL9VCqfUXB6eJ3Kpj+bf9=A@mail.gmail.com
State Not Applicable
Headers show

Commit Message

Yinghai Lu Sept. 9, 2015, 5:22 p.m. UTC 
On Wed, Sep 9, 2015 at 9:59 AM, Yinghai Lu <yinghai@kernel.org> wrote:
> On Wed, Sep 9, 2015 at 4:32 AM, Lorenzo Pieralisi
> <lorenzo.pieralisi@arm.com> wrote:
>> Subject: [PATCH] PCI: remove dead code in pci_claim_bridge_resource()
>>
> That should be regression from c770cb4cb505 ("PCI: Mark invalid BARs
> as unassigned")
> so right fix should be:

completed format as attached:

Comments

Lorenzo Pieralisi Sept. 9, 2015, 5:38 p.m. UTC | #1 
On Wed, Sep 09, 2015 at 06:22:34PM +0100, Yinghai Lu wrote:
> On Wed, Sep 9, 2015 at 9:59 AM, Yinghai Lu <yinghai@kernel.org> wrote:
> > On Wed, Sep 9, 2015 at 4:32 AM, Lorenzo Pieralisi
> > <lorenzo.pieralisi@arm.com> wrote:
> >> Subject: [PATCH] PCI: remove dead code in pci_claim_bridge_resource()
> >>
> > That should be regression from c770cb4cb505 ("PCI: Mark invalid BARs
> > as unassigned")
> > so right fix should be:
> 
> completed format as attached:

> From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Subject: [PATCH] PCI: Fix clipped bridge resource reserve
> 
> Commit 8505e729a2f6eb ("PCI: Add pci_claim_bridge_resource() to clip
> window if necessary") introduced a new API to claim bridge resources.
> pci_claim_bridge_resource() tries to claim a bridge resource, and if
> the claiming fails the function tries to clip the resource to make
> it fit within the parent resource window.
> If the clipping succeeds the bridge apertures are set-up accordingly
> and the pci_claim_bridge_resource() tries to claim the resource
> again.
> 
> Commit c770cb4cb505 ("PCI: Mark invalid BARs as unassigned") added
> code that sets the IORESOURCE_UNSET flag on claiming failure.
> 
> This means that the second resource claiming after window clipping will
> always fail, since the resource flags contain IORESOURCE_UNSET,
> previously set on failure by pci_claim_resource(), so the subsequent
> pci_claim_resource() call ends up spitting a log message and return
> failure with no chance whatsoever to succeed.
> 
> This patch clear the UNSET in resource flags, and it makes second
> pci_claim_resource() work again.
> 
> Fixes: c770cb4cb505 ("PCI: Mark invalid BARs as unassigned")
> Cc: stable@vger.kernel.org [v4.1+]
> [change to clear UNSET instead, Yinghai]
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>

My Signed-off-by is missing, if you do not mind given that I reported
it and I obviously knew this was the real fix (I said that) I will
send the updated patch to the list accordingly or Bjorn can fix it up,
as you both prefer.

Thanks,
Lorenzo

> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 508cc56..76b3349 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -733,6 +733,7 @@ int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
>  		return -EINVAL;
>  	}
>  
> +	bridge->resource[i].flags &= ~IORESOURCE_UNSET;
>  	if (pci_claim_resource(bridge, i) == 0)
>  		return 0;	/* claimed a smaller window */
>  

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diff mbox

Patch

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Subject: [PATCH] PCI: Fix clipped bridge resource reserve

Commit 8505e729a2f6eb ("PCI: Add pci_claim_bridge_resource() to clip
window if necessary") introduced a new API to claim bridge resources.
pci_claim_bridge_resource() tries to claim a bridge resource, and if
the claiming fails the function tries to clip the resource to make
it fit within the parent resource window.
If the clipping succeeds the bridge apertures are set-up accordingly
and the pci_claim_bridge_resource() tries to claim the resource
again.

Commit c770cb4cb505 ("PCI: Mark invalid BARs as unassigned") added
code that sets the IORESOURCE_UNSET flag on claiming failure.

This means that the second resource claiming after window clipping will
always fail, since the resource flags contain IORESOURCE_UNSET,
previously set on failure by pci_claim_resource(), so the subsequent
pci_claim_resource() call ends up spitting a log message and return
failure with no chance whatsoever to succeed.

This patch clear the UNSET in resource flags, and it makes second
pci_claim_resource() work again.

Fixes: c770cb4cb505 ("PCI: Mark invalid BARs as unassigned")
Cc: stable@vger.kernel.org [v4.1+]
[change to clear UNSET instead, Yinghai]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>

diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
index 508cc56..76b3349 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -733,6 +733,7 @@  int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
 		return -EINVAL;
 	}
 
+	bridge->resource[i].flags &= ~IORESOURCE_UNSET;
 	if (pci_claim_resource(bridge, i) == 0)
 		return 0;	/* claimed a smaller window */