USB: HCD: remove logic about which hcd is loaded

-----原始邮件-----
发件人: "Greg Kroah-Hartman" <[email protected]>
发送时间:2026-01-07 23:25:40 (星期三)
收件人: [email protected]
抄送: [email protected], "Greg Kroah-Hartman" <[email protected]>, "Huacai Chen" <[email protected]>, "Alan Stern" <[email protected]> 主题: [PATCH] USB: HCD: remove logic about which hcd is loaded

It turns out that warning about which USB host controller is loaded before another one doesn't really matter. All that really is needed is the PCI softdep module loading logic, which has been present in the kernel ever since commit 05c92da0c524 ("usb: ohci/uhci - add soft dependencies on ehci_pci")

So remove the warning messages, they are not useful, not needed, and only confuse people. As can be seen in the discussion at
https://lore.kernel.org/r/[email protected]

Cc Huacai Chen <[email protected]>

Suggested-by Alan Stern <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

---
 drivers/usb/core/hcd.c            | 4 ----
 drivers/usb/fotg210/fotg210-hcd.c | 6 ------
 drivers/usb/host/ehci-hcd.c       | 8 --------
 drivers/usb/host/ohci-hcd.c       | 3 ---
 drivers/usb/host/uhci-hcd.c       | 5 -----
 include/linux/usb/hcd.h           | 6 ------
 6 files changed, 32 deletions(-)

drivers/usb/core/hcd.c +0 -4

index 24feb0de1c00..2d99a59d9f3f 100644
@@ -77,10 +77,6 @@
 
 /*-------------------------------------------------------------------------*/
 
-/* Keep track of which host controller drivers are loaded */
-unsigned long usb_hcds_loaded;
-EXPORT_SYMBOL_GPL(usb_hcds_loaded);
-
 /* host controllers we manage */
 DEFINE_IDR (usb_bus_idr);
 EXPORT_SYMBOL_GPL (usb_bus_idr);

drivers/usb/fotg210/fotg210-hcd.c +0 -6

index 64c4965a160f..fbb5d590eab6 100644
@@ -5625,11 +5625,6 @@ int __init fotg210_hcd_init(void)
 	if (usb_disabled())
 		return -ENODEV;
 
-	set_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
-	if (test_bit(USB_UHCI_LOADED, &usb_hcds_loaded) ||
-			test_bit(USB_OHCI_LOADED, &usb_hcds_loaded))
-		pr_warn("Warning! fotg210_hcd should always be loaded before uhci_hcd and ohci_hcd, not after\n");
-
 	pr_debug("%s: block sizes: qh %zd qtd %zd itd %zd\n",
 			hcd_name, sizeof(struct fotg210_qh),
 			sizeof(struct fotg210_qtd),

@@ -5643,5 +5638,4 @@ int __init fotg210_hcd_init(void)
 void __exit fotg210_hcd_cleanup(void)
 {
 	debugfs_remove(fotg210_debug_root);
-	clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
 }

drivers/usb/host/ehci-hcd.c +0 -8

index 6d1d190c914d..3c46bb18c7f3 100644
@@ -1354,12 +1354,6 @@ static int __init ehci_hcd_init(void)
 	if (usb_disabled())
 		return -ENODEV;
 
-	set_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
-	if (test_bit(USB_UHCI_LOADED, &usb_hcds_loaded) ||
-			test_bit(USB_OHCI_LOADED, &usb_hcds_loaded))
-		printk(KERN_WARNING "Warning! ehci_hcd should always be loaded"
-				" before uhci_hcd and ohci_hcd, not after\n");
-
 	pr_debug("%s: block sizes: qh %zd qtd %zd itd %zd sitd %zd\n",
 		 hcd_name,
 		 sizeof(struct ehci_qh), sizeof(struct ehci_qtd),

@@ -1390,7 +1384,6 @@ static int __init ehci_hcd_init(void)
 	debugfs_remove(ehci_debug_root);
 	ehci_debug_root = NULL;
 #endif
-	clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
 	return retval;
 }
 module_init(ehci_hcd_init);

@@ -1404,6 +1397,5 @@ static void __exit ehci_hcd_cleanup(void)
 #ifdef CONFIG_DYNAMIC_DEBUG
 	debugfs_remove(ehci_debug_root);
 #endif
-	clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
 }
 module_exit(ehci_hcd_cleanup);

drivers/usb/host/ohci-hcd.c +0 -3

index 9c7f3008646e..30840922f729 100644
@@ -1282,7 +1282,6 @@ static int __init ohci_hcd_mod_init(void)
 
 	pr_debug ("%s: block sizes: ed %zd td %zd\n", hcd_name,
 		sizeof (struct ed), sizeof (struct td));
-	set_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
 
 	ohci_debug_root = debugfs_create_dir("ohci", usb_debug_root);
 

@@ -1332,7 +1331,6 @@ static int __init ohci_hcd_mod_init(void)
 	debugfs_remove(ohci_debug_root);
 	ohci_debug_root = NULL;
 
-	clear_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
 	return retval;
 }
 module_init(ohci_hcd_mod_init);

@@ -1352,7 +1350,6 @@ static void __exit ohci_hcd_mod_exit(void)
 	ps3_ohci_driver_unregister(&PS3_SYSTEM_BUS_DRIVER);
 #endif
 	debugfs_remove(ohci_debug_root);
-	clear_bit(USB_OHCI_LOADED, &usb_hcds_loaded);
 }
 module_exit(ohci_hcd_mod_exit);
 

drivers/usb/host/uhci-hcd.c +0 -5

index 14e6dfef16c6..8bb11109b66c 100644
@@ -867,8 +867,6 @@ static int __init uhci_hcd_init(void)
 	if (usb_disabled())
 		return -ENODEV;
 
-	set_bit(USB_UHCI_LOADED, &usb_hcds_loaded);
-
 #ifdef CONFIG_DYNAMIC_DEBUG
 	errbuf = kmalloc(ERRBUF_LEN, GFP_KERNEL);
 	if (!errbuf)

@@ -912,8 +910,6 @@ static int __init uhci_hcd_init(void)
 
 errbuf_failed:
 #endif
-
-	clear_bit(USB_UHCI_LOADED, &usb_hcds_loaded);
 	return retval;
 }
 

@@ -930,7 +926,6 @@ static void __exit uhci_hcd_cleanup(void)
 #ifdef CONFIG_DYNAMIC_DEBUG
 	kfree(errbuf);
 #endif
-	clear_bit(USB_UHCI_LOADED, &usb_hcds_loaded);
 }
 
 module_init(uhci_hcd_init);

include/linux/usb/hcd.h +0 -6

index ac95e7c89df5..181db044c4d2 100644
@@ -760,12 +760,6 @@ static inline void usbmon_urb_complete(struct usb_bus *bus, struct urb *urb,
  */
 extern struct rw_semaphore ehci_cf_port_reset_rwsem;
 
-/* Keep track of which host controller drivers are loaded */
-#define USB_UHCI_LOADED		0
-#define USB_OHCI_LOADED		1
-#define USB_EHCI_LOADED		2
-extern unsigned long usb_hcds_loaded;
-
 #endif /* __KERNEL__ */
 
 #endif /* __USB_CORE_HCD_H */

Signature · 1 line

2.52.0

Quoted 20 lines

-----原始邮件-----
发件人: "Greg Kroah-Hartman" <[email protected]>
发送时间:2026-01-07 23:25:40 (星期三)
收件人: [email protected]
抄送: [email protected], "Greg Kroah-Hartman" <[email protected]>, "Huacai Chen" <[email protected]>, "Alan Stern" <[email protected]> 主题: [PATCH] USB: HCD: remove logic about which hcd is loaded

It turns out that warning about which USB host controller is loaded before another one doesn't really matter. All that really is needed is the PCI softdep module loading logic, which has been present in the kernel ever since commit 05c92da0c524 ("usb: ohci/uhci - add soft dependencies on ehci_pci")

So remove the warning messages, they are not useful, not needed, and only confuse people. As can be seen in the discussion at
https://lore.kernel.org/r/[email protected]

Quoted 3 lines

Cc Huacai Chen <[email protected]>

Suggested-by Alan Stern <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

Reviewed-by Huacai Chen <[email protected]>

And it should be backported to stable branches?

-----原始邮件-----
发件人: "Greg Kroah-Hartman" <[email protected]>
发送时间:2026-01-10 17:54:10 (星期六)
收件人: 陈华才 <[email protected]>
抄送: [email protected], [email protected], "Alan Stern" <[email protected]> 主题: Re: [PATCH] USB: HCD: remove logic about which hcd is loaded

Quoted 23 lines · 陈华才

Quoted 23 lines

-----原始邮件-----
发件人: "Greg Kroah-Hartman" <[email protected]>
发送时间:2026-01-07 23:25:40 (星期三)
收件人: [email protected]
抄送: [email protected], "Greg Kroah-Hartman" <[email protected]>, "Huacai Chen" <[email protected]>, "Alan Stern" <[email protected]> 主题: [PATCH] USB: HCD: remove logic about which hcd is loaded

It turns out that warning about which USB host controller is loaded before another one doesn't really matter. All that really is needed is the PCI softdep module loading logic, which has been present in the kernel ever since commit 05c92da0c524 ("usb: ohci/uhci - add soft dependencies on ehci_pci")

So remove the warning messages, they are not useful, not needed, and only confuse people. As can be seen in the discussion at
https://lore.kernel.org/r/[email protected]

Cc Huacai Chen <[email protected]>

Suggested-by Alan Stern <[email protected]>

Signed-off-by Greg Kroah-Hartman <[email protected]>

Quoted 3 lines

Reviewed-by Huacai Chen <[email protected]>

And it should be backported to stable branches?

It doesn't change any behavior, so why would it be needed anywhere else? It's just removing a message that people have been ignoring for a very very long time :)

thanks,

greg k-h

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