[PATCH v7 23/26] PCI: Don't claim immovable BARs

From: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
To: <linux-pci@vger.kernel.org>
Cc: Bjorn Helgaas <helgaas@kernel.org>, Stefan Roese <sr@denx.de>,
	<linux@yadro.com>,
	Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
Subject: [PATCH v7 23/26] PCI: Don't claim immovable BARs
Date: Wed, 29 Jan 2020 18:29:34 +0300	[thread overview]
Message-ID: <20200129152937.311162-24-s.miroshnichenko@yadro.com> (raw)
In-Reply-To: <20200129152937.311162-1-s.miroshnichenko@yadro.com>

Immovable BAR always has an address, but its parent bridge window can
be not yet calculated (during boot) or temporarily released for re-
calculation (during PCI rescan) when pci_claim_resource() is called.

Apart from that, immovable BARs now have separate guaranteed mechanism
of assigning comparing to usual BARs, so claiming them is not needed.

Return immediately from pci_claim_resource() to prevent misleading
"can't claim BAR ... no compatible bridge window" error messages

Signed-off-by: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
---
 drivers/pci/setup-res.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 4043aab021dd..dc9b52f11922 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -138,6 +138,9 @@ int pci_claim_resource(struct pci_dev *dev, int resource)
 		return -EINVAL;
 	}
 
+	if (pci_can_move_bars && !pci_dev_bar_movable(dev, res))
+		return 0;
+
 	/*
 	 * If we have a shadow copy in RAM, the PCI device doesn't respond
 	 * to the shadow range, so we don't need to claim it, and upstream
-- 
2.24.1

