[PATCH v2 1/2] usb: dwc3: use local copy of resource to fix-up register offset

From: Masahiro Yamada
Date: Thu Apr 19 2018 - 07:05:24 EST


It is not a good idea to directly modify the resource of a platform
device. Modify its local copy, and pass it to devm_ioremap_resource()
so that we do not need to restore it in the failure path and the remove
hook.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Reviewed-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
---

Changes in v2: None

drivers/usb/dwc3/core.c | 32 ++++++++------------------------
1 file changed, 8 insertions(+), 24 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index a15648d..8e66edd 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -1245,7 +1245,7 @@ static void dwc3_check_params(struct dwc3 *dwc)
static int dwc3_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
- struct resource *res;
+ struct resource *res, dwc_res;
struct dwc3 *dwc;

int ret;
@@ -1270,20 +1270,19 @@ static int dwc3_probe(struct platform_device *pdev)
dwc->xhci_resources[0].flags = res->flags;
dwc->xhci_resources[0].name = res->name;

- res->start += DWC3_GLOBALS_REGS_START;
-
/*
* Request memory region but exclude xHCI regs,
* since it will be requested by the xhci-plat driver.
*/
- regs = devm_ioremap_resource(dev, res);
- if (IS_ERR(regs)) {
- ret = PTR_ERR(regs);
- goto err0;
- }
+ dwc_res = *res;
+ dwc_res.start += DWC3_GLOBALS_REGS_START;
+
+ regs = devm_ioremap_resource(dev, &dwc_res);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);

dwc->regs = regs;
- dwc->regs_size = resource_size(res);
+ dwc->regs_size = resource_size(&dwc_res);

dwc3_get_properties(dwc);

@@ -1350,29 +1349,14 @@ static int dwc3_probe(struct platform_device *pdev)
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);

-err0:
- /*
- * restore res->start back to its original value so that, in case the
- * probe is deferred, we don't end up getting error in request the
- * memory region the next time probe is called.
- */
- res->start -= DWC3_GLOBALS_REGS_START;
-
return ret;
}

static int dwc3_remove(struct platform_device *pdev)
{
struct dwc3 *dwc = platform_get_drvdata(pdev);
- struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

pm_runtime_get_sync(&pdev->dev);
- /*
- * restore res->start back to its original value so that, in case the
- * probe is deferred, we don't end up getting error in request the
- * memory region the next time probe is called.
- */
- res->start -= DWC3_GLOBALS_REGS_START;

dwc3_debugfs_exit(dwc);
dwc3_core_exit_mode(dwc);
--
2.7.4