diff mbox series

[v4,07/12] PCI: dwc: Avoid reading a register to detect whether eDMA exists

Message ID 20220722110744.2274466-8-yoshihiro.shimoda.uh@renesas.com (mailing list archive)
State Superseded
Headers show
Series treewide: PCI: renesas: Add R-Car Gen4 PCIe support | expand

Commit Message

Yoshihiro Shimoda July 22, 2022, 11:07 a.m. UTC 
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 mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index e04128a22bbe..8a274953e25d 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -839,8 +839,7 @@  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);
@@ -848,6 +847,7 @@  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;
 	}