linux/drivers/usb/core/message.c, branch v4.9

usb: core: setup dma_pfn_offset for USB devices and, interfaces

2016-09-13T15:25:35Z

If dma_pfn_offset is not inherited correctly from the host controller, it might result in sub-optimal configuration as bounce buffer limit might be set to less than optimal level. Consider the mass storage device case. USB storage driver creates a scsi host for the mass storage interface in drivers/usb/storage/usb.c The scsi host parent device is nothing but the the USB interface device. Now, __scsi_init_queue() calls scsi_calculate_bounce_limit() to find out and set the block layer bounce limit. scsi_calculate_bounce_limit() uses dma_max_pfn(host_dev) to get the bounce_limit. host_dev is nothing but the device representing the mass storage interface. If that device doesn't have the right dma_pfn_offset, then dma_max_pfn() is messed up and the bounce buffer limit is wrong. e.g. On Keystone 2 systems, dma_max_pfn() is 0x87FFFF and dma_mask_pfn is 0xFFFFF. Consider a mass storage use case: Without this patch, usb scsi host device (usb-storage) will get a dma_pfn_offset of 0 resulting in a dma_max_pfn() of 0xFFFFF within the scsi layer (scsi_calculate_bounce_limit()). This will result in bounce buffers being unnecessarily used. Hint: On 32-bit ARM platforms dma_max_pfn() = dma_mask_pfn + dma_pfn_offset Signed-off-by: Roger Quadros Acked-by: Arnd Bergmann Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman

usb: core: message: don't print on ENOMEM

2016-08-30T17:17:36Z

All kmalloc-based functions print enough information on failures. Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman

usbnet: move the CDC parser into USB core

2016-07-18T15:46:57Z

The dependencies were impossible to handle preventing drivers for CDC devices not which are not network drivers from using the common parser. Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman

drivers: usb: core: Minimize irq disabling in usb_sg_cancel()

2016-04-26T22:21:41Z

Restructure usb_sg_cancel() so we don't have to disable interrupts while cancelling the URBs. Suggested-by: Alan Stern Signed-off-by: David Mosberger Signed-off-by: Greg Kroah-Hartman

drivers: usb: core: Don't disable irqs in usb_sg_wait() during URB submit.

2016-04-26T22:21:41Z

usb_submit_urb() may take quite long to execute. For example, a single sg list may have 30 or more entries, possibly leading to that many calls to DMA-map pages. This can cause interrupt latency of several hundred micro-seconds. Avoid the problem by releasing the io->lock spinlock and re-enabling interrupts before calling usb_submit_urb(). This opens races with usb_sg_cancel() and sg_complete(). Handle those races by using usb_block_urb() to stop URBs from being submitted after usb_sg_cancel() or sg_complete() with error. Note that usb_unlink_urb() is guaranteed to return -ENODEV if !io->urbs[i]->dev and since the -ENODEV case is already handled, we don't have to check for !io->urbs[i]->dev explicitly. Before this change, reading 512MB from an ext3 filesystem on a USB memory stick showed a throughput of 12 MB/s with about 500 missed deadlines. With this change, reading the same file gave the same throughput but only one or two missed deadlines. Signed-off-by: David Mosberger Signed-off-by: Greg Kroah-Hartman

usb: message: remove redundant declaration

2015-10-04T09:45:11Z

Fix the Sparse warning: message.c:1390:21: warning: symbol 'i' shadows an earlier one message.c:1294:13: originally declared here Signed-off-by: Kris Borer Signed-off-by: Greg Kroah-Hartman

usb: interface authorization: Introduces the USB interface authorization

2015-09-22T19:08:40Z

The kernel supports the device authorization because of wireless USB. These is usable for wired USB devices, too. These new interface authorization allows to enable or disable individual interfaces instead a whole device. If a deauthorized interface will be authorized so the driver probing must be triggered manually by writing INTERFACE to /sys/bus/usb/drivers_probe Signed-off-by: Stefan Koch Signed-off-by: Greg Kroah-Hartman

usb: interface authorization: Introduces the default interface authorization

2015-09-22T19:08:40Z

Interfaces are allowed per default. This can disabled or enabled (again) by writing 0 or 1 to /sys/bus/usb/devices/usbX/interface_authorized_default Signed-off-by: Stefan Koch Signed-off-by: Greg Kroah-Hartman

USB: don't cancel queued resets when unbinding drivers

2015-01-25T12:54:17Z

The USB stack provides a mechanism for drivers to request an asynchronous device reset (usb_queue_reset_device()). The mechanism uses a work item (reset_ws) embedded in the usb_interface structure used by the driver, and the reset is carried out by a work queue routine. The asynchronous reset can race with driver unbinding. When this happens, we try to cancel the queued reset before unbinding the driver, on the theory that the driver won't care about any resets once it is unbound. However, thanks to the fact that lockdep now tracks work queue accesses, this can provoke a lockdep warning in situations where the device reset causes another interface's driver to be unbound; see http://marc.info/?l=linux-usb&m=141893165203776&w=2 for an example. The reason is that the work routine for reset_ws in one interface calls cancel_queued_work() for the reset_ws in another interface. Lockdep thinks this might lead to a work routine trying to cancel itself. The simplest solution is not to cancel queued resets when unbinding drivers. This means we now need to acquire a reference to the usb_interface when queuing a reset_ws work item and to drop the reference when the work routine finishes. We also need to make sure that the usb_interface structure doesn't outlive its parent usb_device; this means acquiring and dropping a reference when the interface is created and destroyed. In addition, cancelling a queued reset can fail (if the device is in the middle of an earlier reset), and this can cause usb_reset_device() to try to rebind an interface that has been deallocated (see http://marc.info/?l=linux-usb&m=142175717016628&w=2 for details). Acquiring the extra references prevents this failure. Signed-off-by: Alan Stern Reported-by: Russell King - ARM Linux Reported-by: Olivier Sobrie Tested-by: Olivier Sobrie Cc: stable # 3.19 Signed-off-by: Greg Kroah-Hartman

usb: core: log higher level message on malformed LANGID descriptor

2014-09-29T01:54:26Z

Commit 0cce2eda19923e5e5ccc8b042dec5af87b3ffad0 USB: fix LANGID=0 regression defaults to a langid of 0x0409 if it's not properly implemented by the device. Explain with a higher level error message what this means. Signed-off-by: Scot Doyle Signed-off-by: Greg Kroah-Hartman