[PATCH] usb: ehci-fsl: Fix use of private data to avoid -Wflex-array-member-not-at-end warning
From: Alan Stern
Date: Thu Mar 27 2025 - 15:31:27 EST
In the course of fixing up the usages of flexible arrays, Gustavo
submitted a patch updating the ehci-fsl driver. However, the patch
was wrong because the driver was using the .priv member of the
ehci_hcd structure incorrectly. The private data is not supposed to
be a wrapper containing the ehci_hcd structure; it is supposed to be a
sub-structure stored in the .priv member.
Fix the problem by replacing the ehci_fsl structure with
ehci_fsl_priv, containing only the private data, along with a suitable
conversion macro for accessing it. This removes the problem of having
data follow a flexible array member.
Reported-by: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/linux-usb/Z-R9BcnSzrRv5FX_@kspp/
---
drivers/usb/host/ehci-fsl.c | 25 ++++++++-----------------
1 file changed, 8 insertions(+), 17 deletions(-)
Index: usb-devel/drivers/usb/host/ehci-fsl.c
===================================================================
--- usb-devel.orig/drivers/usb/host/ehci-fsl.c
+++ usb-devel/drivers/usb/host/ehci-fsl.c
@@ -410,15 +410,13 @@ static int ehci_fsl_setup(struct usb_hcd
return retval;
}
-struct ehci_fsl {
- struct ehci_hcd ehci;
-
-#ifdef CONFIG_PM
+struct ehci_fsl_priv {
/* Saved USB PHY settings, need to restore after deep sleep. */
u32 usb_ctrl;
-#endif
};
+#define hcd_to_ehci_fsl_priv(h) ((struct ehci_fsl_priv *) hcd_to_ehci(h)->priv)
+
#ifdef CONFIG_PM
#ifdef CONFIG_PPC_MPC512x
@@ -566,17 +564,10 @@ static inline int ehci_fsl_mpc512x_drv_r
}
#endif /* CONFIG_PPC_MPC512x */
-static struct ehci_fsl *hcd_to_ehci_fsl(struct usb_hcd *hcd)
-{
- struct ehci_hcd *ehci = hcd_to_ehci(hcd);
-
- return container_of(ehci, struct ehci_fsl, ehci);
-}
-
static int ehci_fsl_drv_suspend(struct device *dev)
{
struct usb_hcd *hcd = dev_get_drvdata(dev);
- struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
+ struct ehci_fsl_priv *priv = hcd_to_ehci_fsl_priv(hcd);
void __iomem *non_ehci = hcd->regs;
if (of_device_is_compatible(dev->parent->of_node,
@@ -589,14 +580,14 @@ static int ehci_fsl_drv_suspend(struct d
if (!fsl_deep_sleep())
return 0;
- ehci_fsl->usb_ctrl = ioread32be(non_ehci + FSL_SOC_USB_CTRL);
+ priv->usb_ctrl = ioread32be(non_ehci + FSL_SOC_USB_CTRL);
return 0;
}
static int ehci_fsl_drv_resume(struct device *dev)
{
struct usb_hcd *hcd = dev_get_drvdata(dev);
- struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
+ struct ehci_fsl_priv *priv = hcd_to_ehci_fsl_priv(hcd);
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
void __iomem *non_ehci = hcd->regs;
@@ -612,7 +603,7 @@ static int ehci_fsl_drv_resume(struct de
usb_root_hub_lost_power(hcd->self.root_hub);
/* Restore USB PHY settings and enable the controller. */
- iowrite32be(ehci_fsl->usb_ctrl, non_ehci + FSL_SOC_USB_CTRL);
+ iowrite32be(priv->usb_ctrl, non_ehci + FSL_SOC_USB_CTRL);
ehci_reset(ehci);
ehci_fsl_reinit(ehci);
@@ -671,7 +662,7 @@ static int ehci_start_port_reset(struct
#endif /* CONFIG_USB_OTG */
static const struct ehci_driver_overrides ehci_fsl_overrides __initconst = {
- .extra_priv_size = sizeof(struct ehci_fsl),
+ .extra_priv_size = sizeof(struct ehci_fsl_priv),
.reset = ehci_fsl_setup,
};