[patch 11/12] usb: core: Replace in_interrupt() in comments

From: Thomas Gleixner
Date: Wed Oct 14 2020 - 11:20:02 EST


From: Ahmed S. Darwish <a.darwish@xxxxxxxxxxxxx>

The usage of in_interrupt() in drivers is phased out for various reasons.

Various comments use !in_interrupt() to describe calling context for
functions which might sleep. That's wrong because the calling context has
to be preemptible task context, which is not what !in_interrupt()
describes.

Replace !in_interrupt() with more accurate plain text descriptions.

The comment for usb_hcd_poll_rh_status() is misleading as this function is
called from all kinds of contexts including preemptible task
context. Remove it as there is obviously no restriction.

Signed-off-by: Ahmed S. Darwish <a.darwish@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx

---
drivers/usb/core/buffer.c | 6 ++++--
drivers/usb/core/hcd-pci.c | 6 ++++--
drivers/usb/core/hcd.c | 21 +++++++++++----------
drivers/usb/core/hub.c | 3 ++-
drivers/usb/core/message.c | 35 ++++++++++++++++++++++-------------
drivers/usb/core/usb.c | 4 ++--
6 files changed, 45 insertions(+), 30 deletions(-)

--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -51,7 +51,8 @@ void __init usb_init_pool_max(void)
/**
* hcd_buffer_create - initialize buffer pools
* @hcd: the bus whose buffer pools are to be initialized
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep
*
* Call this as part of initializing a host controller that uses the dma
* memory allocators. It initializes some pools of dma-coherent memory that
@@ -88,7 +89,8 @@ int hcd_buffer_create(struct usb_hcd *hc
/**
* hcd_buffer_destroy - deallocate buffer pools
* @hcd: the bus whose buffer pools are to be destroyed
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep
*
* This frees the buffer pools created by hcd_buffer_create().
*/
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -160,7 +160,8 @@ static void ehci_wait_for_companions(str
* @dev: USB Host Controller being probed
* @id: pci hotplug id connecting controller to HCD framework
* @driver: USB HC driver handle
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep
*
* Allocates basic PCI resources for this USB host controller, and
* then invokes the start() method for the HCD associated with it
@@ -304,7 +305,8 @@ EXPORT_SYMBOL_GPL(usb_hcd_pci_probe);
/**
* usb_hcd_pci_remove - shutdown processing for PCI-based HCDs
* @dev: USB Host Controller being removed
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep
*
* Reverses the effect of usb_hcd_pci_probe(), first invoking
* the HCD's stop() method. It is always called from a thread
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -746,9 +746,6 @@ static int rh_call_control (struct usb_h
* Root Hub interrupt transfers are polled using a timer if the
* driver requests it; otherwise the driver is responsible for
* calling usb_hcd_poll_rh_status() when an event occurs.
- *
- * Completions are called in_interrupt(), but they may or may not
- * be in_irq().
*/
void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
{
@@ -904,7 +901,8 @@ static void usb_bus_init (struct usb_bus
/**
* usb_register_bus - registers the USB host controller with the usb core
* @bus: pointer to the bus to register
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep.
*
* Assigns a bus number, and links the controller into usbcore data
* structures so that it can be seen by scanning the bus list.
@@ -939,7 +937,8 @@ static int usb_register_bus(struct usb_b
/**
* usb_deregister_bus - deregisters the USB host controller
* @bus: pointer to the bus to deregister
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep.
*
* Recycles the bus number, and unlinks the controller from usbcore data
* structures so that it won't be seen by scanning the bus list.
@@ -1691,7 +1690,6 @@ static void usb_giveback_urb_bh(unsigned
* @hcd: host controller returning the URB
* @urb: urb being returned to the USB device driver.
* @status: completion status code for the URB.
- * Context: in_interrupt()
*
* This hands the URB from HCD to its USB device driver, using its
* completion function. The HCD has freed all per-urb resources
@@ -2268,7 +2266,7 @@ EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hu
* usb_bus_start_enum - start immediate enumeration (for OTG)
* @bus: the bus (must use hcd framework)
* @port_num: 1-based number of port; usually bus->otg_port
- * Context: in_interrupt()
+ * Context: atomic
*
* Starts enumeration, with an immediate reset followed later by
* hub_wq identifying and possibly configuring the device.
@@ -2474,7 +2472,8 @@ EXPORT_SYMBOL_GPL(__usb_create_hcd);
* @bus_name: value to store in hcd->self.bus_name
* @primary_hcd: a pointer to the usb_hcd structure that is sharing the
* PCI device. Only allocate certain resources for the primary HCD
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep.
*
* Allocate a struct usb_hcd, with extra space at the end for the
* HC driver's private data. Initialize the generic members of the
@@ -2496,7 +2495,8 @@ EXPORT_SYMBOL_GPL(usb_create_shared_hcd)
* @driver: HC driver that will use this hcd
* @dev: device for this HC, stored in hcd->self.controller
* @bus_name: value to store in hcd->self.bus_name
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep.
*
* Allocate a struct usb_hcd, with extra space at the end for the
* HC driver's private data. Initialize the generic members of the
@@ -2830,7 +2830,8 @@ EXPORT_SYMBOL_GPL(usb_add_hcd);
/**
* usb_remove_hcd - shutdown processing for generic HCDs
* @hcd: the usb_hcd structure to remove
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep.
*
* Disconnects the root hub, then reverses the effects of usb_add_hcd(),
* invoking the HCD's stop() method.
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2171,7 +2171,8 @@ static void hub_disconnect_children(stru
/**
* usb_disconnect - disconnect a device (usbcore-internal)
* @pdev: pointer to device being disconnected
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep
*
* Something got disconnected. Get rid of it and all of its children.
*
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -119,7 +119,7 @@ static int usb_internal_control_msg(stru
* @timeout: time in msecs to wait for the message to complete before timing
* out (if 0 the wait is forever)
*
- * Context: !in_interrupt ()
+ * Context: task context, might sleep.
*
* This function sends a simple control message to a specified endpoint and
* waits for the message to complete, or timeout.
@@ -173,7 +173,7 @@ EXPORT_SYMBOL_GPL(usb_control_msg);
* @timeout: time in msecs to wait for the message to complete before
* timing out (if 0 the wait is forever)
*
- * Context: !in_interrupt ()
+ * Context: task context, might sleep.
*
* This function sends a simple interrupt message to a specified endpoint and
* waits for the message to complete, or timeout.
@@ -206,7 +206,7 @@ EXPORT_SYMBOL_GPL(usb_interrupt_msg);
* @timeout: time in msecs to wait for the message to complete before
* timing out (if 0 the wait is forever)
*
- * Context: !in_interrupt ()
+ * Context: task context, might sleep.
*
* This function sends a simple bulk message to a specified endpoint
* and waits for the message to complete, or timeout.
@@ -473,7 +473,8 @@ EXPORT_SYMBOL_GPL(usb_sg_init);
* usb_sg_wait - synchronously execute scatter/gather request
* @io: request block handle, as initialized with usb_sg_init().
* some fields become accessible when this call returns.
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep.
*
* This function blocks until the specified I/O operation completes. It
* leverages the grouping of the related I/O requests to get good transfer
@@ -627,7 +628,8 @@ EXPORT_SYMBOL_GPL(usb_sg_cancel);
* @index: the number of the descriptor
* @buf: where to put the descriptor
* @size: how big is "buf"?
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep.
*
* Gets a USB descriptor. Convenience functions exist to simplify
* getting some types of descriptors. Use
@@ -675,7 +677,8 @@ EXPORT_SYMBOL_GPL(usb_get_descriptor);
* @index: the number of the descriptor
* @buf: where to put the string
* @size: how big is "buf"?
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep.
*
* Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
* in little-endian byte order).
@@ -810,7 +813,8 @@ static int usb_get_langid(struct usb_dev
* @index: the number of the descriptor
* @buf: where to put the string
* @size: how big is "buf"?
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep.
*
* This converts the UTF-16LE encoded strings returned by devices, from
* usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
@@ -899,7 +903,8 @@ char *usb_cache_string(struct usb_device
* usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
* @dev: the device whose device descriptor is being updated
* @size: how much of the descriptor to read
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep.
*
* Updates the copy of the device descriptor stored in the device structure,
* which dedicates space for this purpose.
@@ -934,7 +939,7 @@ int usb_get_device_descriptor(struct usb
/*
* usb_set_isoch_delay - informs the device of the packet transmit delay
* @dev: the device whose delay is to be informed
- * Context: !in_interrupt()
+ * Context: can sleep
*
* Since this is an optional request, we don't bother if it fails.
*/
@@ -962,7 +967,8 @@ int usb_set_isoch_delay(struct usb_devic
* @type: USB_STATUS_TYPE_*; for standard or PTM status types
* @target: zero (for device), else interface or endpoint number
* @data: pointer to two bytes of bitmap data
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep.
*
* Returns device, interface, or endpoint status. Normally only of
* interest to see if the device is self powered, or has enabled the
@@ -1039,7 +1045,8 @@ EXPORT_SYMBOL_GPL(usb_get_status);
* usb_clear_halt - tells device to clear endpoint halt/stall condition
* @dev: device whose endpoint is halted
* @pipe: endpoint "pipe" being cleared
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep.
*
* This is used to clear halt conditions for bulk and interrupt endpoints,
* as reported by URB completion status. Endpoints that are halted are
@@ -1343,7 +1350,8 @@ void usb_enable_interface(struct usb_dev
* @dev: the device whose interface is being updated
* @interface: the interface being updated
* @alternate: the setting being chosen.
- * Context: !in_interrupt ()
+ *
+ * Context: task context, might sleep.
*
* This is used to enable data transfers on interfaces that may not
* be enabled by default. Not all devices support such configurability.
@@ -1762,7 +1770,8 @@ static void __usb_queue_reset_device(str
* usb_set_configuration - Makes a particular device setting be current
* @dev: the device whose configuration is being updated
* @configuration: the configuration being chosen.
- * Context: !in_interrupt(), caller owns the device lock
+ *
+ * Context: task context, might sleep. Caller holds device lock.
*
* This is used to enable non-default device modes. Not all devices
* use this kind of configurability; many devices only have one
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -28,7 +28,6 @@
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/slab.h>
-#include <linux/interrupt.h> /* for in_interrupt() */
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/spinlock.h>
@@ -561,7 +560,8 @@ static bool usb_dev_authorized(struct us
* @parent: hub to which device is connected; null to allocate a root hub
* @bus: bus used to access the device
* @port1: one-based index of port; ignored for root hubs
- * Context: !in_interrupt()
+ *
+ * Context: task context, might sleep.
*
* Only hub drivers (including virtual root hub drivers for host
* controllers) should ever call this.