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From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
To: lpieralisi@kernel.org, robh+dt@kernel.org, kw@linux.com,
	bhelgaas@google.com, krzk+dt@kernel.org, geert+renesas@glider.be,
	magnus.damm@gmail.com
Cc: marek.vasut+renesas@gmail.com, linux-pci@vger.kernel.org,
	devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Subject: [PATCH v5 07/12] PCI: dwc: Avoid reading a register to detect whether eDMA exists
Date: Mon,  5 Sep 2022 16:12:52 +0900	[thread overview]
Message-ID: <20220905071257.1059436-8-yoshihiro.shimoda.uh@renesas.com> (raw)
In-Reply-To: <20220905071257.1059436-1-yoshihiro.shimoda.uh@renesas.com>

Since reading value of PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL was
0x00000000 on one of SoCs (R-Car S4-8), it cannot find the eDMA.
So, directly read the eDMA register if edma.red_base is not zero.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
---
 drivers/pci/controller/dwc/pcie-designware.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 72f9620a374d..08f91a6bbe4b 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -844,8 +844,7 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
 {
 	u32 val;
 
-	val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
-	if (val == 0xFFFFFFFF && pci->edma.reg_base) {
+	if (pci->edma.reg_base) {
 		pci->edma.mf = EDMA_MF_EDMA_UNROLL;
 
 		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
@@ -853,6 +852,7 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
 		pci->edma.mf = EDMA_MF_EDMA_LEGACY;
 
 		pci->edma.reg_base = pci->dbi_base + PCIE_DMA_VIEWPORT_BASE;
+		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
 	} else {
 		return -ENODEV;
 	}
-- 
2.25.1


  parent reply	other threads:[~2022-09-05  7:19 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-05  7:12 [PATCH v5 00/12] treewide: PCI: renesas: Add R-Car Gen4 PCIe support Yoshihiro Shimoda
2022-09-05  7:12 ` [PATCH v5 01/12] dt-bindings: PCI: renesas: Add R-Car Gen4 PCIe Host Yoshihiro Shimoda
2022-09-05  7:12 ` [PATCH v5 02/12] dt-bindings: PCI: renesas: Add R-Car Gen4 PCIe Endpoint Yoshihiro Shimoda
2022-09-05  7:12 ` [PATCH v5 03/12] PCI: Add PCI_EXP_LNKCAP_MLW macros Yoshihiro Shimoda
2022-09-20 20:08   ` Bjorn Helgaas
2022-09-21  0:05     ` Yoshihiro Shimoda
2022-09-21  2:22       ` Bjorn Helgaas
2022-09-21  8:50         ` Yoshihiro Shimoda
2022-09-05  7:12 ` [PATCH v5 04/12] PCI: controller: dwc: Expose dw_pcie_ep_exit() to module Yoshihiro Shimoda
2022-09-20 20:00   ` Bjorn Helgaas
2022-09-05  7:12 ` [PATCH v5 05/12] PCI: dwc: Add ep_pre_init() callback to dw_pcie_ep_ops Yoshihiro Shimoda
2022-09-20 20:03   ` Bjorn Helgaas
2022-09-05  7:12 ` [PATCH v5 06/12] PCI: dwc: Add reset_all_bars flag Yoshihiro Shimoda
2022-09-05  7:12 ` Yoshihiro Shimoda [this message]
2022-09-05  8:39   ` [PATCH v5 07/12] PCI: dwc: Avoid reading a register to detect whether eDMA exists Sergei Shtylyov
2022-09-05 13:13     ` Yoshihiro Shimoda
2022-09-05  7:12 ` [PATCH v5 08/12] PCI: renesas: Add R-Car Gen4 PCIe Host support Yoshihiro Shimoda
2022-09-20 19:59   ` Bjorn Helgaas
2022-09-05  7:12 ` [PATCH v5 09/12] PCI: renesas: Add R-Car Gen4 PCIe Endpoint support Yoshihiro Shimoda
2022-09-05  7:12 ` [PATCH v5 10/12] MAINTAINERS: Update PCI DRIVER FOR RENESAS R-CAR for R-Car Gen4 Yoshihiro Shimoda
2022-09-05  7:12 ` [PATCH v5 11/12] arm64: dts: renesas: r8a779f0: Add PCIe Host and Endpoint nodes Yoshihiro Shimoda
2022-09-05  7:12 ` [PATCH v5 12/12] arm64: dts: renesas: r8a779f0: spider: Enable PCIe Host ch0 Yoshihiro Shimoda

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