net: ethernet: ti: cpsw: fix bad register access in probe error path

Make sure to keep the platform device runtime-resumed throughout probe
to avoid accessing the CPSW registers in the error path (e.g. for
deferred probe) with clocks disabled:

Unhandled fault: external abort on non-linefetch (0x1008) at 0xd0872d08
...
[<c04fabcc>] (cpsw_ale_control_set) from [<c04fb8b4>] (cpsw_ale_destroy+0x2c/0x44)
[<c04fb8b4>] (cpsw_ale_destroy) from [<c04fea58>] (cpsw_probe+0xbd0/0x10c4)
[<c04fea58>] (cpsw_probe) from [<c047b2a0>] (platform_drv_probe+0x5c/0xc0)

Fixes: df828598a755 ("netdev: driver: ethernet: Add TI CPSW driver")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 4 deletions

diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
index c6cff3d2ff05..f60f8ab7c1e3 100644
--- a/drivers/net/ethernet/ti/cpsw.c
+++ b/drivers/net/ethernet/ti/cpsw.c
@@ -2641,13 +2641,12 @@ static int cpsw_probe(struct platform_device *pdev)
                 goto clean_runtime_disable_ret;
         }
         cpsw->version = readl(&cpsw->regs->id_ver);
-        pm_runtime_put_sync(&pdev->dev);
 
         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
         cpsw->wr_regs = devm_ioremap_resource(&pdev->dev, res);
         if (IS_ERR(cpsw->wr_regs)) {
                 ret = PTR_ERR(cpsw->wr_regs);
-                goto clean_runtime_disable_ret;
+                goto clean_pm_runtime_put_ret;
         }
 
         memset(&dma_params, 0, sizeof(dma_params));
@@ -2684,7 +2683,7 @@ static int cpsw_probe(struct platform_device *pdev)
         default:
                 dev_err(priv->dev, "unknown version 0x%08x\n", cpsw->version);
                 ret = -ENODEV;
-                goto clean_runtime_disable_ret;
+                goto clean_pm_runtime_put_ret;
         }
         for (i = 0; i < cpsw->data.slaves; i++) {
                 struct cpsw_slave *slave = &cpsw->slaves[i];
@@ -2713,7 +2712,7 @@ static int cpsw_probe(struct platform_device *pdev)
         if (!cpsw->dma) {
                 dev_err(priv->dev, "error initializing dma\n");
                 ret = -ENOMEM;
-                goto clean_runtime_disable_ret;
+                goto clean_pm_runtime_put_ret;
         }
 
         cpsw->txch[0] = cpdma_chan_create(cpsw->dma, 0, cpsw_tx_handler, 0);
@@ -2815,12 +2814,16 @@ static int cpsw_probe(struct platform_device *pdev)
                 }
         }
 
+        pm_runtime_put(&pdev->dev);
+
         return 0;
 
 clean_ale_ret:
         cpsw_ale_destroy(cpsw->ale);
 clean_dma_ret:
         cpdma_ctlr_destroy(cpsw->dma);
+clean_pm_runtime_put_ret:
+        pm_runtime_put_sync(&pdev->dev);
 clean_runtime_disable_ret:
         pm_runtime_disable(&pdev->dev);
 clean_ndev_ret: