[PATCH v3 1/2] PCI: dwc: Add .post_deinit counterpart to endpoint .pre_init callback

If .pre_init() succeeds but subsequent initialization fails, it is
mandatory to correctly undo the hardware configuration which the
.pre_init() callback did. Intrododuce .post_deinit() callback to do
exactly that, undo what the .pre_init() callback did. Usually, that
means stop the clock, assert reset, and possibly program some registers
to quiescense the hardware. Invoke the .post_deinit() callback in
dw_pcie_ep_deinit() to retain functional symmetry.

Reviewed-by: Koichiro Den <[email protected]>
Tested-by: Koichiro Den <[email protected]>
Signed-off-by: Marek Vasut <[email protected]>
---
Cc: "Krzysztof Wilczyński" <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Koichiro Den <[email protected]>
Cc: Lorenzo Pieralisi <[email protected]>
Cc: Magnus Damm <[email protected]>
Cc: Manivannan Sadhasivam <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Yoshihiro Shimoda <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
V2: New patch
V3: - Update commit message slightly
    - Add RB/TB from Den-san
---
 drivers/pci/controller/dwc/pcie-designware-ep.c | 8 +++++++-
 drivers/pci/controller/dwc/pcie-designware.h    | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index de8ee3db43601..1a3491b5003ec 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -1194,6 +1194,9 @@ void dw_pcie_ep_deinit(struct dw_pcie_ep *ep)
 			      epc->mem->window.page_size);
 
 	pci_epc_mem_exit(epc);
+
+	if (ep->ops->post_deinit)
+		ep->ops->post_deinit(ep);
 }
 EXPORT_SYMBOL_GPL(dw_pcie_ep_deinit);
 
@@ -1553,7 +1556,7 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 			       ep->page_size);
 	if (ret < 0) {
 		dev_err(dev, "Failed to initialize address space\n");
-		return ret;
+		goto err_deinit;
 	}
 
 	ep->msi_mem = pci_epc_mem_alloc_addr(epc, &ep->msi_mem_phys,
@@ -1568,6 +1571,9 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 
 err_exit_epc_mem:
 	pci_epc_mem_exit(epc);
+err_deinit:
+	if (ep->ops->post_deinit)
+		ep->ops->post_deinit(ep);
 
 	return ret;
 }
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 0735ae9409240..a53ac27cd2447 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -475,6 +475,7 @@ struct dw_pcie_rp {
 
 struct dw_pcie_ep_ops {
 	int	(*pre_init)(struct dw_pcie_ep *ep);
+	void	(*post_deinit)(struct dw_pcie_ep *ep);
 	int	(*init)(struct dw_pcie_ep *ep);
 	int	(*raise_irq)(struct dw_pcie_ep *ep, u8 func_no,
 			     unsigned int type, u16 interrupt_num);
-- 
2.53.0