Linux PCI subsystem development
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From: Shawn Lin <shawn.lin@rock-chips.com>
To: Manivannan Sadhasivam <mani@kernel.org>,
	Jingoo Han <jingoohan1@gmail.com>,
	Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-rockchip@lists.infradead.org,
	Niklas Cassel <cassel@kernel.org>,
	linux-pci@vger.kernel.org, Shawn Lin <shawn.lin@rock-chips.com>
Subject: [PATCH] PCI: dw-rockchip: Disable BAR 0 and BAR 1 for RC mode
Date: Wed, 24 Dec 2025 18:01:01 +0800	[thread overview]
Message-ID: <1766570461-138256-1-git-send-email-shawn.lin@rock-chips.com> (raw)

To slitence the useless bar allocation error log of RC when
scanning bus, as RC doesn't need BARs at all.

  pci 0000:00:00.0: [1d87:3588] type 01 class 0x060400 PCIe Root Port
  pci 0000:00:00.0: BAR 0 [mem 0x00000000-0x3fffffff]
  pci 0000:00:00.0: BAR 1 [mem 0x00000000-0x3fffffff]
  pci 0000:00:00.0: ROM [mem 0x00000000-0x0000ffff pref]
	...
  pci 0000:00:00.0: BAR 0 [mem 0x900000000-0x93fffffff]: assigned
  pci 0000:00:00.0: BAR 1 [mem size 0x40000000]: can't assign; no space
  pci 0000:00:00.0: BAR 1 [mem size 0x40000000]: failed to assign
  pci 0000:00:00.0: ROM [mem 0xf0200000-0xf020ffff pref]: assigned
  pci 0000:00:00.0: BAR 0 [mem 0x900000000-0x93fffffff]: releasing
  pci 0000:00:00.0: ROM [mem 0xf0200000-0xf020ffff pref]: releasing
  pci 0000:00:00.0: BAR 0 [mem 0x900000000-0x93fffffff]: assigned
  pci 0000:00:00.0: BAR 1 [mem size 0x40000000]: can't assign; no space
  pci 0000:00:00.0: BAR 1 [mem size 0x40000000]: failed to assign

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---

 drivers/pci/controller/dwc/pcie-dw-rockchip.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-dw-rockchip.c b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
index f8605fe..e421fa0 100644
--- a/drivers/pci/controller/dwc/pcie-dw-rockchip.c
+++ b/drivers/pci/controller/dwc/pcie-dw-rockchip.c
@@ -80,6 +80,8 @@
 #define  PCIE_LINKUP_MASK		GENMASK(17, 16)
 #define  PCIE_LTSSM_STATUS_MASK		GENMASK(5, 0)
 
+#define PCIE_TYPE0_HDR_DBI2_OFFSET      0x100000
+
 struct rockchip_pcie {
 	struct dw_pcie pci;
 	void __iomem *apb_base;
@@ -292,6 +294,8 @@ static int rockchip_pcie_host_init(struct dw_pcie_rp *pp)
 	if (irq < 0)
 		return irq;
 
+	pci->dbi_base2 = pci->dbi_base + PCIE_TYPE0_HDR_DBI2_OFFSET;
+
 	ret = rockchip_pcie_init_irq_domain(rockchip);
 	if (ret < 0)
 		dev_err(dev, "failed to init irq domain\n");
@@ -302,6 +306,10 @@ static int rockchip_pcie_host_init(struct dw_pcie_rp *pp)
 	rockchip_pcie_configure_l1ss(pci);
 	rockchip_pcie_enable_l0s(pci);
 
+	/* Disable RC's BAR0 and BAR1 */
+	dw_pcie_writel_dbi2(pci, PCI_BASE_ADDRESS_0, 0x0);
+	dw_pcie_writel_dbi2(pci, PCI_BASE_ADDRESS_1, 0x0);
+
 	return 0;
 }
 
-- 
2.7.4


             reply	other threads:[~2025-12-24 10:06 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-12-24 10:01 Shawn Lin [this message]
2026-01-13 14:29 ` [PATCH] PCI: dw-rockchip: Disable BAR 0 and BAR 1 for RC mode Manivannan Sadhasivam
2026-01-14  1:32   ` Shawn Lin
2026-01-14  7:38     ` Manivannan Sadhasivam
2026-01-14  7:37 ` Manivannan Sadhasivam

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