usb: sandbox: Fix emulator device select logic in usb_emul_find_devnum()

Current emulator select logic in usb_emul_find_devnum() is to test
the USB address. The USB address of the device being enumerated is
initialized to zero at the beginning of the enumeration process in
usb_setup_device(). At this point, the saved USB address in the
platform data has not been assigned to any valid USB address either.
This means: the logic will select an emulator device according to
its sequence of declaring order in the device tree. Take test.dts
for example, flash-stick@0 will be selected before flash-stick@1.
But unfortunately such logic is wrong.

In fact USB devices show up in a random order during the enumeration
which means usb_emul_find_devnum() may be called on port 3 for keyb@3
before on port 0 for flash-stick@0.

To fix this, we introduce a new emulator uclass specific platdata
to store the USB device's port number on its parent hub, and update
the logic to test the port number instead.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/drivers/usb/emul/sandbox_hub.c b/drivers/usb/emul/sandbox_hub.c
index 9ed700036e0ac9fae424f0a4b85f179c1cc82683..8ed7a0f43456510e4c1008dac9b57b9c90ba9c18 100644 (file)
--- a/drivers/usb/emul/sandbox_hub.c
+++ b/drivers/usb/emul/sandbox_hub.c
@@ -280,8 +280,10 @@ static int sandbox_hub_bind(struct udevice *dev)
 static int sandbox_child_post_bind(struct udevice *dev)
 {
        struct sandbox_hub_platdata *plat = dev_get_parent_platdata(dev);
+       struct usb_emul_platdata *emul = dev_get_uclass_platdata(dev);
 
        plat->port = dev_read_u32_default(dev, "reg", -1);
+       emul->port1 = plat->port + 1;
 
        return 0;
 }

diff --git a/drivers/usb/emul/usb-emul-uclass.c b/drivers/usb/emul/usb-emul-uclass.c
index e4a267bf00ac251bad3527b54de337f489a1cfd3..1203eb2f11a8e88dc22aa6def5fa509d5eb5e5d2 100644 (file)
--- a/drivers/usb/emul/usb-emul-uclass.c
+++ b/drivers/usb/emul/usb-emul-uclass.c
@@ -107,7 +107,7 @@ static int usb_emul_get_descriptor(struct usb_dev_platdata *plat, int value,
        return upto ? upto : length ? -EIO : 0;
 }
 
-static int usb_emul_find_devnum(int devnum, struct udevice **emulp)
+static int usb_emul_find_devnum(int devnum, int port1, struct udevice **emulp)
 {
        struct udevice *dev;
        struct uclass *uc;
@@ -120,7 +120,37 @@ static int usb_emul_find_devnum(int devnum, struct udevice **emulp)
        uclass_foreach_dev(dev, uc) {
                struct usb_dev_platdata *udev = dev_get_parent_platdata(dev);
 
-               if (udev->devnum == devnum) {
+               /*
+                * devnum is initialzied to zero at the beginning of the
+                * enumeration process in usb_setup_device(). At this
+                * point, udev->devnum has not been assigned to any valid
+                * USB address either, so we can't rely on the comparison
+                * result between udev->devnum and devnum to select an
+                * emulator device.
+                */
+               if (!devnum) {
+                       struct usb_emul_platdata *plat;
+
+                       /*
+                        * If the parent is sandbox USB controller, we are
+                        * the root hub. And there is only one root hub
+                        * in the system.
+                        */
+                       if (device_get_uclass_id(dev->parent) == UCLASS_USB) {
+                               debug("%s: Found emulator '%s'\n",
+                                     __func__, dev->name);
+                               *emulp = dev;
+                               return 0;
+                       }
+
+                       plat = dev_get_uclass_platdata(dev);
+                       if (plat->port1 == port1) {
+                               debug("%s: Found emulator '%s', port %d\n",
+                                     __func__, dev->name, port1);
+                               *emulp = dev;
+                               return 0;
+                       }
+               } else if (udev->devnum == devnum) {
                        debug("%s: Found emulator '%s', addr %d\n", __func__,
                              dev->name, udev->devnum);
                        *emulp = dev;
@@ -132,18 +162,19 @@ static int usb_emul_find_devnum(int devnum, struct udevice **emulp)
        return -ENOENT;
 }
 
-int usb_emul_find(struct udevice *bus, ulong pipe, struct udevice **emulp)
+int usb_emul_find(struct udevice *bus, ulong pipe, int port1,
+                 struct udevice **emulp)
 {
        int devnum = usb_pipedevice(pipe);
 
-       return usb_emul_find_devnum(devnum, emulp);
+       return usb_emul_find_devnum(devnum, port1, emulp);
 }
 
 int usb_emul_find_for_dev(struct udevice *dev, struct udevice **emulp)
 {
        struct usb_dev_platdata *udev = dev_get_parent_platdata(dev);
 
-       return usb_emul_find_devnum(udev->devnum, emulp);
+       return usb_emul_find_devnum(udev->devnum, 0, emulp);
 }
 
 int usb_emul_control(struct udevice *emul, struct usb_device *udev,
@@ -276,6 +307,7 @@ UCLASS_DRIVER(usb_emul) = {
        .id             = UCLASS_USB_EMUL,
        .name           = "usb_emul",
        .post_bind      = dm_scan_fdt_dev,
+       .per_device_platdata_auto_alloc_size = sizeof(struct usb_emul_platdata),
        .per_child_auto_alloc_size = sizeof(struct usb_device),
        .per_child_platdata_auto_alloc_size = sizeof(struct usb_dev_platdata),
 };

diff --git a/drivers/usb/host/usb-sandbox.c b/drivers/usb/host/usb-sandbox.c
index f85d36ba429b7f19cbd7184c0298519cf6f6ca11..15055b351a5a5a5b25724f3173422b2085991458 100644 (file)
--- a/drivers/usb/host/usb-sandbox.c
+++ b/drivers/usb/host/usb-sandbox.c
@@ -50,7 +50,7 @@ static int sandbox_submit_control(struct udevice *bus,
 
        /* Just use child of dev as emulator? */
        debug("%s: bus=%s\n", __func__, bus->name);
-       ret = usb_emul_find(bus, pipe, &emul);
+       ret = usb_emul_find(bus, pipe, udev->portnr, &emul);
        usbmon_trace(bus, pipe, setup, emul);
        if (ret)
                return ret;
@@ -83,7 +83,7 @@ static int sandbox_submit_bulk(struct udevice *bus, struct usb_device *udev,
 
        /* Just use child of dev as emulator? */
        debug("%s: bus=%s\n", __func__, bus->name);
-       ret = usb_emul_find(bus, pipe, &emul);
+       ret = usb_emul_find(bus, pipe, udev->portnr, &emul);
        usbmon_trace(bus, pipe, NULL, emul);
        if (ret)
                return ret;
@@ -109,7 +109,7 @@ static int sandbox_submit_int(struct udevice *bus, struct usb_device *udev,
 
        /* Just use child of dev as emulator? */
        debug("%s: bus=%s\n", __func__, bus->name);
-       ret = usb_emul_find(bus, pipe, &emul);
+       ret = usb_emul_find(bus, pipe, udev->portnr, &emul);
        usbmon_trace(bus, pipe, NULL, emul);
        if (ret)
                return ret;

diff --git a/include/usb.h b/include/usb.h
index 3d517316e5b034d50c04cab9015060529565d42c..63eddddc914fb35717278fc546be8e683d02755f 100644 (file)
--- a/include/usb.h
+++ b/include/usb.h
@@ -652,6 +652,18 @@ struct usb_bus_priv {
        bool companion;
 };
 
+/**
+ * struct usb_emul_platdata - platform data about the USB emulator
+ *
+ * Given a USB emulator (UCLASS_USB_EMUL) 'dev', this is
+ * dev_get_uclass_platdata(dev).
+ *
+ * @port1:     USB emulator device port number on the parent hub
+ */
+struct usb_emul_platdata {
+       int port1;      /* Port number (numbered from 1) */
+};
+
 /**
  * struct dm_usb_ops - USB controller operations
  *
@@ -1023,14 +1035,16 @@ int usb_emul_int(struct udevice *emul, struct usb_device *udev,
 /**
  * usb_emul_find() - Find an emulator for a particular device
  *
- * Check @pipe to find a device number on bus @bus and return it.
+ * Check @pipe and @port1 to find a device number on bus @bus and return it.
  *
  * @bus:       USB bus (controller)
  * @pipe:      Describes pipe being used, and includes the device number
+ * @port1:     Describes port number on the parent hub
  * @emulp:     Returns pointer to emulator, or NULL if not found
  * @return 0 if found, -ve on error
  */
-int usb_emul_find(struct udevice *bus, ulong pipe, struct udevice **emulp);
+int usb_emul_find(struct udevice *bus, ulong pipe, int port1,
+                 struct udevice **emulp);
 
 /**
  * usb_emul_find_for_dev() - Find an emulator for a particular device