[usb] Maintain single lists of halted endpoints and changed ports

When an EHCI hotplug action results in the controller disowning the
port, it will result in a hotplug action on the corresponding UHCI or
OHCI controller.  Allow such hotplug actions to be carried out as part
of the same call to usb_step() or usb_register_bus(), by maintaining a
single central list of changed ports.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/drivers/bus/usb.c b/src/drivers/bus/usb.c
index 3484cba13a2b4e4030352397e296d6b43f1595f6..16f182595762d77cab81cb9590df276ee2f07b47 100644 (file)
--- a/src/drivers/bus/usb.c
+++ b/src/drivers/bus/usb.c
@@ -43,6 +43,12 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 /** List of USB buses */
 struct list_head usb_buses = LIST_HEAD_INIT ( usb_buses );
 
+/** List of changed ports */
+static struct list_head usb_changed = LIST_HEAD_INIT ( usb_changed );
+
+/** List of halted endpoints */
+static struct list_head usb_halted = LIST_HEAD_INIT ( usb_halted );
+
 /******************************************************************************
  *
  * Utility functions
@@ -560,7 +566,6 @@ int usb_stream ( struct usb_endpoint *ep, struct io_buffer *iobuf,
 void usb_complete_err ( struct usb_endpoint *ep, struct io_buffer *iobuf,
                        int rc ) {
        struct usb_device *usb = ep->usb;
-       struct usb_bus *bus = usb->port->hub->bus;
 
        /* Decrement fill level */
        assert ( ep->fill > 0 );
@@ -572,7 +577,7 @@ void usb_complete_err ( struct usb_endpoint *ep, struct io_buffer *iobuf,
                       usb->name, usb_endpoint_name ( ep->address ),
                       strerror ( rc ) );
                list_del ( &ep->halted );
-               list_add_tail ( &ep->halted, &bus->halted );
+               list_add_tail ( &ep->halted, &usb_halted );
        }
 
        /* Report completion */
@@ -1576,12 +1581,12 @@ static void usb_detached ( struct usb_port *port ) {
 }
 
 /**
- * Handle newly attached or detached USB devices
+ * Handle newly attached or detached USB device
  *
  * @v port             USB port
  * @ret rc             Return status code
  */
-static int usb_hotplug ( struct usb_port *port ) {
+static int usb_hotplugged ( struct usb_port *port ) {
        struct usb_hub *hub = port->hub;
        int rc;
 
@@ -1621,43 +1626,26 @@ static int usb_hotplug ( struct usb_port *port ) {
  * @v port             USB port
  */
 void usb_port_changed ( struct usb_port *port ) {
-       struct usb_hub *hub = port->hub;
-       struct usb_bus *bus = hub->bus;
 
        /* Record hub port status change */
        list_del ( &port->changed );
-       list_add_tail ( &port->changed, &bus->changed );
+       list_add_tail ( &port->changed, &usb_changed );
 }
 
 /**
- * USB process
+ * Handle newly attached or detached USB device
  *
- * @v bus              USB bus
  */
-static void usb_step ( struct usb_bus *bus ) {
-       struct usb_endpoint *ep;
+static void usb_hotplug ( void ) {
        struct usb_port *port;
 
-       /* Poll bus */
-       usb_poll ( bus );
-
-       /* Attempt to reset first halted endpoint in list, if any.  We
-        * do not attempt to process the complete list, since this
-        * would require extra code to allow for the facts that the
-        * halted endpoint list may change as we do so, and that
-        * resetting an endpoint may fail.
-        */
-       if ( ( ep = list_first_entry ( &bus->halted, struct usb_endpoint,
-                                      halted ) ) != NULL )
-               usb_endpoint_reset ( ep );
-
        /* Handle any changed ports, allowing for the fact that the
         * port list may change as we perform hotplug actions.
         */
-       while ( ! list_empty ( &bus->changed ) ) {
+       while ( ! list_empty ( &usb_changed ) ) {
 
                /* Get first changed port */
-               port = list_first_entry ( &bus->changed, struct usb_port,
+               port = list_first_entry ( &usb_changed, struct usb_port,
                                          changed );
                assert ( port != NULL );
 
@@ -1666,13 +1654,39 @@ static void usb_step ( struct usb_bus *bus ) {
                INIT_LIST_HEAD ( &port->changed );
 
                /* Perform appropriate hotplug action */
-               usb_hotplug ( port );
+               usb_hotplugged ( port );
        }
 }
 
+/**
+ * USB process
+ *
+ * @v process          USB process
+ */
+static void usb_step ( struct process *process __unused ) {
+       struct usb_bus *bus;
+       struct usb_endpoint *ep;
+
+       /* Poll all buses */
+       for_each_usb_bus ( bus )
+               usb_poll ( bus );
+
+       /* Attempt to reset first halted endpoint in list, if any.  We
+        * do not attempt to process the complete list, since this
+        * would require extra code to allow for the facts that the
+        * halted endpoint list may change as we do so, and that
+        * resetting an endpoint may fail.
+        */
+       if ( ( ep = list_first_entry ( &usb_halted, struct usb_endpoint,
+                                      halted ) ) != NULL )
+               usb_endpoint_reset ( ep );
+
+       /* Handle any changed ports */
+       usb_hotplug();
+}
+
 /** USB process */
-static struct process_descriptor usb_process_desc =
-       PROC_DESC ( struct usb_bus, process, usb_step );
+PERMANENT_PROCESS ( usb_process, usb_step );
 
 /******************************************************************************
  *
@@ -1755,10 +1769,10 @@ int register_usb_hub ( struct usb_hub *hub ) {
        /* Delay to allow ports to stabilise */
        mdelay ( USB_PORT_DELAY_MS );
 
-       /* Attach any devices already present */
+       /* Mark all ports as changed */
        for ( i = 1 ; i <= hub->ports ; i++ ) {
                port = usb_port ( hub, i );
-               usb_hotplug ( port );
+               usb_port_changed ( port );
        }
 
        /* Some hubs seem to defer reporting device connections until
@@ -1766,7 +1780,10 @@ int register_usb_hub ( struct usb_hub *hub ) {
         * Poll the bus once now in order to pick up any such
         * connections.
         */
-       usb_step ( bus );
+       usb_poll ( bus );
+
+       /* Attach any devices already present */
+       usb_hotplug();
 
        return 0;
 
@@ -1862,9 +1879,6 @@ struct usb_bus * alloc_usb_bus ( struct device *dev, unsigned int ports,
        bus->op = op;
        INIT_LIST_HEAD ( &bus->devices );
        INIT_LIST_HEAD ( &bus->hubs );
-       INIT_LIST_HEAD ( &bus->changed );
-       INIT_LIST_HEAD ( &bus->halted );
-       process_init_stopped ( &bus->process, &usb_process_desc, NULL );
        bus->host = &bus->op->bus;
 
        /* Allocate root hub */
@@ -1904,9 +1918,6 @@ int register_usb_bus ( struct usb_bus *bus ) {
        if ( ( rc = register_usb_hub ( bus->hub ) ) != 0 )
                goto err_register_hub;
 
-       /* Start bus process */
-       process_add ( &bus->process );
-
        return 0;
 
        unregister_usb_hub ( bus->hub );
@@ -1926,10 +1937,6 @@ void unregister_usb_bus ( struct usb_bus *bus ) {
 
        /* Sanity checks */
        assert ( bus->hub != NULL );
-       assert ( process_running ( &bus->process ) );
-
-       /* Stop bus process */
-       process_del ( &bus->process );
 
        /* Unregister root hub */
        unregister_usb_hub ( bus->hub );
@@ -1943,7 +1950,6 @@ void unregister_usb_bus ( struct usb_bus *bus ) {
        /* Sanity checks */
        assert ( list_empty ( &bus->devices ) );
        assert ( list_empty ( &bus->hubs ) );
-       assert ( ! process_running ( &bus->process ) );
 }
 
 /**
@@ -1952,11 +1958,16 @@ void unregister_usb_bus ( struct usb_bus *bus ) {
  * @v bus              USB bus
  */
 void free_usb_bus ( struct usb_bus *bus ) {
+       struct usb_endpoint *ep;
+       struct usb_port *port;
 
        /* Sanity checks */
        assert ( list_empty ( &bus->devices ) );
        assert ( list_empty ( &bus->hubs ) );
-       assert ( ! process_running ( &bus->process ) );
+       list_for_each_entry ( ep, &usb_halted, halted )
+               assert ( ep->usb->port->hub->bus != bus );
+       list_for_each_entry ( port, &usb_changed, changed )
+               assert ( port->hub->bus != bus );
 
        /* Free root hub */
        free_usb_hub ( bus->hub );

diff --git a/src/include/ipxe/usb.h b/src/include/ipxe/usb.h
index d326678c8d763398c09c942de0783ca4f931fff8..ee826bc117c5f16582979d50df08bf90d80a7b89 100644 (file)
--- a/src/include/ipxe/usb.h
+++ b/src/include/ipxe/usb.h
@@ -922,12 +922,6 @@ struct usb_bus {
        struct list_head devices;
        /** List of hubs */
        struct list_head hubs;
-       /** List of changed ports */
-       struct list_head changed;
-       /** List of halted endpoints */
-       struct list_head halted;
-       /** Process */
-       struct process process;
 
        /** Host controller operations */
        struct usb_bus_host_operations *host;