linux/drivers/usb/core
Sebastian Andrzej Siewior 5efd2ea8c9 usb: core: buffer: smallest buffer should start at ARCH_DMA_MINALIGN
the following error pops up during "testusb -a -t 10"
| musb-hdrc musb-hdrc.1.auto: dma_pool_free buffer-128,	f134e000/be842000 (bad dma)
hcd_buffer_create() creates a few buffers, the smallest has 32 bytes of
size. ARCH_KMALLOC_MINALIGN is set to 64 bytes. This combo results in
hcd_buffer_alloc() returning memory which is 32 bytes aligned and it
might by identified by buffer_offset() as another buffer. This means the
buffer which is on a 32 byte boundary will not get freed, instead it
tries to free another buffer with the error message.

This patch fixes the issue by creating the smallest DMA buffer with the
size of ARCH_KMALLOC_MINALIGN (or 32 in case ARCH_KMALLOC_MINALIGN is
smaller). This might be 32, 64 or even 128 bytes. The next three pools
will have the size 128, 512 and 2048.
In case the smallest pool is 128 bytes then we have only three pools
instead of four (and zero the first entry in the array).
The last pool size is always 2048 bytes which is the assumed PAGE_SIZE /
2 of 4096. I doubt it makes sense to continue using PAGE_SIZE / 2 where
we would end up with 8KiB buffer in case we have 16KiB pages.
Instead I think it makes sense to have a common size(s) and extend them
if there is need to.
There is a BUILD_BUG_ON() now in case someone has a minalign of more than
128 bytes.

Cc: stable@vger.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 10:21:31 -08:00
..
buffer.c usb: core: buffer: smallest buffer should start at ARCH_DMA_MINALIGN 2015-01-09 10:21:31 -08:00
config.c usb-core bInterval quirk 2014-08-01 15:47:05 -07:00
devices.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
devio.c USB: devio: fix issue with log flooding 2014-08-01 16:01:46 -07:00
driver.c USB / PM: Drop CONFIG_PM_RUNTIME from the USB core 2014-12-04 00:51:54 +01:00
endpoint.c USB: core: be specific about attribute permissions 2013-08-25 15:12:03 -07:00
file.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
generic.c staging: usbip: convert usbip-host driver to usb_device_driver 2014-02-07 10:54:30 -08:00
hcd-pci.c USB / PM: Drop CONFIG_PM_RUNTIME from the USB core 2014-12-04 00:51:54 +01:00
hcd.c USB patches for 3.19-rc1 2014-12-14 14:57:16 -08:00
hub.c USB patches for 3.19-rc1 2014-12-14 14:57:16 -08:00
hub.h usb: hub: convert khubd into workqueue 2014-09-23 22:33:19 -07:00
Kconfig PM / Kconfig: Replace PM_RUNTIME with PM in dependencies 2014-12-13 00:44:04 +01:00
Makefile USB: core: remove CONFIG_USB_DEBUG usage 2013-12-21 16:01:00 -08:00
message.c usb: core: log higher level message on malformed LANGID descriptor 2014-09-28 21:54:26 -04:00
notify.c usb: Add export.h for EXPORT_SYMBOL/THIS_MODULE where needed 2011-10-31 19:31:25 -04:00
otg_whitelist.h usb: core: TPL should apply for both OTG and EH 2014-09-23 21:28:41 -07:00
port.c USB / PM: Drop CONFIG_PM_RUNTIME from the USB core 2014-12-04 00:51:54 +01:00
quirks.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2014-12-12 10:26:47 -08:00
sysfs.c USB / PM: Drop CONFIG_PM_RUNTIME from the USB core 2014-12-04 00:51:54 +01:00
urb.c usb: core: allow zero packet flag for interrupt urbs 2014-07-22 16:30:58 -07:00
usb-acpi.c usb: find internal hub tier mismatch via acpi 2014-05-27 16:38:52 -07:00
usb.c usb: core: buffer: smallest buffer should start at ARCH_DMA_MINALIGN 2015-01-09 10:21:31 -08:00
usb.h USB / PM: Drop CONFIG_PM_RUNTIME from the USB core 2014-12-04 00:51:54 +01:00