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path: root/drivers/pci/controller/dwc/pcie-designware.c
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Diffstat (limited to 'drivers/pci/controller/dwc/pcie-designware.c')
-rw-r--r--drivers/pci/controller/dwc/pcie-designware.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 2b60d20dfd..250cf7f40b 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -365,6 +365,7 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val)
if (ret)
dev_err(pci->dev, "write DBI address failed\n");
}
+EXPORT_SYMBOL_GPL(dw_pcie_write_dbi2);
static inline void __iomem *dw_pcie_select_atu(struct dw_pcie *pci, u32 dir,
u32 index)
@@ -887,8 +888,14 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
* Indirect eDMA CSRs access has been completely removed since v5.40a
* thus no space is now reserved for the eDMA channels viewport and
* former DMA CTRL register is no longer fixed to FFs.
+ *
+ * Note that Renesas R-Car S4-8's PCIe controllers for unknown reason
+ * have zeros in the eDMA CTRL register even though the HW-manual
+ * explicitly states there must FFs if the unrolled mapping is enabled.
+ * For such cases the low-level drivers are supposed to manually
+ * activate the unrolled mapping to bypass the auto-detection procedure.
*/
- if (dw_pcie_ver_is_ge(pci, 540A))
+ if (dw_pcie_ver_is_ge(pci, 540A) || dw_pcie_cap_is(pci, EDMA_UNROLL))
val = 0xFFFFFFFF;
else
val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);