Current code doesn't really enable the usb clocks so if they're disabled
when booting linux, the kernel/machine will hang as soon as someone is trying
to read a usb register
Signed-off-by: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (75 commits)
pppoe.c: Fix kernel panic caused by __pppoe_xmit
WAN: Fix a TX IRQ causing BUG() in PC300 and PCI200SYN drivers.
bnx2x: Advance a version number to 1.60.01-0
bnx2x: Fixed a compilation warning
bnx2x: LSO code was broken on BE platforms
qlge: Fix deadlock when cancelling worker.
net: fix skb_defer_rx_timestamp()
cxgb4vf: Ingress Queue Entry Size needs to be 64 bytes
phy: add the IC+ IP1001 driver
atm: correct sysfs 'device' link creation and parent relationships
MAINTAINERS: remove me from tulip
SCTP: Fix SCTP_SET_PEER_PRIMARY_ADDR to accpet v4mapped address
enic: Bug Fix: Pass napi reference to the isr that services receive queue
ipv6: fix nl group when advertising a new link
connector: add module alias
net: Document the kernel_recvmsg() function
r8169: Fix runtime power management
hso: IP checksuming doesn't work on GE0301 option cards
xfrm: Fix xfrm_state_migrate leak
net: Convert netpoll blocking api in bonding driver to be a counter
...
The ATM subsystem was incorrectly creating the 'device' link for ATM
nodes in sysfs. This led to incorrect device/parent relationships
exposed by sysfs and udev. Instead of rolling the 'device' link by hand
in the generic ATM code, pass each ATM driver's bus device down to the
sysfs code and let sysfs do this stuff correctly.
Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commits 2eb42d5c28 and
9e1dde3387 renamed some defines
but didn't fix all the places where these defines are used
leading to a compile failure for USB on i.MX31, 35 and 27.
Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This patch (as1437) fixes a bug in the usb-serial autosuspend
handling. Since the usb-serial core now has autosuspend support, it
must set the .supports_autosuspend member in every serial driver it
registers. Otherwise the usb_autopm_get_interface() call won't work.
This fixes Bugzilla #23012.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: stable@kernel.org
Reported-by: Kevin Smith <thirdwiggin@gmail.com>
Reported-and-tested-by: Simon Gerber <gesimu@gmail.com>
Reported-and-tested-by: Matteo Croce <matteo@openwrt.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Tested on MacBookAir3,1. Without this, we get EPROTO errors when
fetching device config descriptors.
Signed-off-by: Brian Tarricone <brian@tarricone.org>
Reported-by: Benoit Gschwind <gschwind@gnu-log.net>
Tested-by: Edgar Hucek <gimli@dark-green.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add the PID for the Vardaan Enterprises VEUSB422R3 USB to RS422/485
converter. It uses the same chip as the FTDI_8U232AM_PID 0x6001.
This should also work with the stable branches for:
2.6.31, 2.6.32, 2.6.33, 2.6.34, 2.6.35, 2.6.36
Signed-off-by: Jacques Viviers <jacques.viviers@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Default llseek operation behavior was changed by the patch named
"vfs: make no_llseek the default" after the yurex driver had been merged,
so the llseek to yurex is now ignored.
This patch add llseek fop with default_llseek to yurex driver
to catch up to the change.
Signed-off-by: Tomoki Sekiyama <tomoki.sekiyama@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Another variant of the RT Systems programming cable for ham radios.
Signed-off-by: Michael Stuermer <ms@mallorn.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The CNS3XXX SOC has include USB EHCI and OHCI compatible controllers.
This patch adds the necessary glue logic to allow ehci-hcd and ohci-hcd
drivers to work on CNS3XXX
The EHCI and OHCI controllers share a common clock control and reset
bit, therefore additional check for the timming of enabling and disabling
is required. The USB bit of PLL Power Down Control is also shared by OTG,
24MHzUART clock, Crypto clock, PCIe reference clock, and Clock Scale
Generator. Therefore we only ensure it is enabled, while not disabling it.
Signed-off-by: Mac Lin <mkl0301@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
The Inventra DMA engine used with the MUSB controller in many
SoCs cannot use DMA for control transfers on EP0, but can use
DMA for all other transfers.
The USB core maps urbs for DMA if hcd->self.uses_dma is true.
(hcd->self.uses_dma is true for MUSB as well).
Split the uses_dma flag into two - one that says if the
controller needs to use PIO for control transfers, and
another which says if the controller uses DMA (for all
other transfers).
Also, populate this flag for all MUSB by default.
(Tested on OMAP3 and OMAP4 boards, with EHCI and MUSB HCDs
simultaneously in use).
Signed-off-by: Maulik Mankad <x0082077@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Cc: Oliver Neukum <oliver@neukum.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Praveena NADAHALLY <praveen.nadahally@stericsson.com>
Cc: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Fixes below compilation warning when musb driver is compiled for
PIO mode:
drivers/usb/musb/musb_gadget.c: In function 'musb_g_rx':
drivers/usb/musb/musb_gadget.c:840:
warning: label 'exit' defined but not used
Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
If RXCSR_AUTOCLEAR flag is not cleard before PIO reading, one packet
may be recieved by musb fifo, but no chance to notify
software, so cause packet loss, follows the detailed process:
- PIO read one packet
- musb fifo auto clear the MUSB_RXCSR_RXPKTRDY
- musb continue to recieve the next packet, and MUSB_RXCSR_RXPKTRDY
is set
- software clear the MUSB_RXCSR_RXPKTRDY, so there is no chance for
musb to notify software that the 2nd recieved packet.
The patch does fix the g_ether issue below:
- use fifo_mode 3 to enable double buffer
- 'ping -s 1024 IP_OF_BEAGLE_XM'
- one usb packet of 512 byte is lost, so ping failed,
which can be observed by wireshark
note:
Beagle xm takes musb rtl1.8 and may fallback to pio mode
for unaligned buffer.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Buffer is mapped to dma when dma channel is
allocated. If, for some reason, dma channel
programming fails, musb code will fallback
to PIO mode to transfer that request. In
that case, we need to unmap the buffer
back to CPU.
MUSB RTL1.8 and above cannot handle buffers
which are not 32bit aligned. That happens to
every request sent by g_ether gadget
driver. Since the buffer sent was unaligned,
we need to fallback to PIO.
Because of that, g_ether was failing due
to missing buffer unmapping.
With this patch and [1] g_ether works fine
with all MUSB revisions.
Verified with OMAP3630 board, which has
MUSB RTL1.8 using g_ether and g_zero.
[1] http://www.spinics.net/lists/linux-usb/msg38400.html
Signed-off-by: Hema HK <hemahk@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Disabling SuperSpeed ports is a Very Bad Thing (TM). It disables
SuperSpeed terminations, which means that devices will never connect at
SuperSpeed on that port. For USB 2.0/1.1 ports, disabling the port meant
that the USB core could always get a connect status change later. That's
not true with USB 3.0 ports.
Do not let the USB core disable SuperSpeed ports. We can't rely on the
device speed in the port status registers, since that isn't valid until
there's a USB device connected to the port. Instead, we use the port
speed array that's created from the Extended Capabilities registers.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Don Zickus <dzickus@redhat.com>
Cc: stable@kernel.org
An xHCI host controller contains USB 2.0 and USB 3.0 ports, which can
occur in any order in the PORTSC registers. We cannot read the port speed
bits in the PORTSC registers at init time to determine the port speed,
since those bits are only valid when a USB device is plugged into the
port.
Instead, we read the "Supported Protocol Capability" registers in the xHC
Extended Capabilities space. Those describe the protocol, port offset in
the PORTSC registers, and port count. We use those registers to create
two arrays of pointers to the PORTSC registers, one for USB 3.0 ports, and
another for USB 2.0 ports. A third array keeps track of the port protocol
major revision, and is indexed with the internal xHCI port number.
This commit is a bit big, but it should be queued for stable because the "Don't
let the USB core disable SuperSpeed ports" patch depends on it. There is no
other way to determine which ports are SuperSpeed ports without this patch.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Don Zickus <dzickus@redhat.com>
Cc: stable@kernel.org
We have been having problems with the USB-IF Gold Tree tests when plugging
and unplugging devices from the tree. I have seen that the reset-device
and configure-endpoint commands, which are invoked from
xhci_discover_or_reset_device() and xhci_configure_endpoint(), will sometimes
time out.
After much debugging, I determined that the commands themselves do not actually
time out, but rather their completion events do not get delivered to the right
place.
This happens when the command ring has just wrapped around, and it's enqueue
pointer is left pointing to the link TRB. xhci_discover_or_reset_device() and
xhci_configure_endpoint() use the enqueue pointer directly as their command
TRB pointer, without checking whether it's pointing to the link TRB.
When the completion event arrives, if the command TRB is pointing to the link
TRB, the check against the command ring dequeue pointer in
handle_cmd_in_cmd_wait_list() fails, so the completion inside the command does
not get signaled.
The patch below fixes the timeout problem for me.
This should be queued for the 2.6.35 and 2.6.36 stable trees.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch (as1435) fixes an obscure and unlikely race in ehci-hcd.
When an async URB is unlinked, the corresponding QH is removed from
the async list. If the QH's endpoint is then disabled while the URB
is being given back, ehci_endpoint_disable() won't find the QH on the
async list, causing it to believe that the QH has been lost. This
will lead to a memory leak at best and quite possibly to an oops.
The solution is to trust usbcore not to lose track of endpoints. If
the QH isn't on the async list then it doesn't need to be taken off
the list, but the driver should still wait for the QH to become IDLE
before disabling it.
In theory this fixes Bugzilla #20182. In fact the race is so rare
that it's not possible to tell whether the bug is still present.
However, adding delays and making other changes to force the race
seems to show that the patch works.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
CC: David Brownell <david-b@pacbell.net>
CC: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix section mismatch warning by using "__devinit" annotation for isp1362_probe.
WARNING: drivers/usb/host/isp1362-hcd.o(.data+0x0): Section mismatch in reference from the variable isp1362_driver to the function .init.text:isp1362_probe()
The variable isp1362_driver references
the function __init isp1362_probe()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On AMD SB700/SB800/Hudson-2/3 platforms, USB EHCI controller may read/write
to memory space not allocated to USB controller if there is longer than
normal latency on DMA read encountered. In this condition the exposure will
be encountered only if the driver has following format of Periodic Frame
List link pointer structure:
For any idle periodic schedule, the Frame List link pointers that have the
T-bit set to 1 intending to terminate the use of frame list link pointer
as a physical memory pointer.
Idle periodic schedule Frame List Link pointer shoule be in the following
format to avoid the issue:
Frame list link pointer should be always contains a valid pointer to a
inactive QHead with T-bit set to 0.
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.
The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.
Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)
Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.
Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
They should not be writable by any user.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hao Wu <hao.wu@intel.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Alek Du <alek.du@intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
They should not be writable by any user.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Harrison Metzger <harrisonmetz@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
They should not be writable by any user.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
It should not be writable by any user.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Sam Hocevar <sam@zoy.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
They should not be writable by any user.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oliver Bock <bock@tfh-berlin.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The permissions for the lpm debugfs file is incorrect, this fixes it.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alek Du <alek.du@intel.com>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some of the sysfs files had the incorrect permissions. Some didn't make
sense at all (writable for a file that you could not write to?)
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthieu Castet <castet.matthieu@free.fr>
Cc: Stanislaw Gruszka <stf_xl@wp.pl>
Cc: Damien Bergamini <damien.bergamini@free.fr>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Andiry's xHCI bus suspend patch introduced the possibly of a host
controller replaying old commands on the command ring, if the host
successfully restores the registers after a resume.
After a resume from suspend, the xHCI driver must restore the registers,
including the command ring pointer. I had suggested that Andiry set the
command ring pointer to the current command ring dequeue pointer, so that
the driver wouldn't have to zero the command ring.
Unfortunately, setting the command ring pointer to the current dequeue
pointer won't work because the register assumes the pointer is 64-byte
aligned, and TRBs on the command ring are 16-byte aligned. The lower
seven bits will always be masked off, leading to the written pointer being
up to 3 TRBs behind the intended pointer.
Here's a log excerpt. On init, the xHCI driver places a vendor-specific
command on the command ring:
[ 215.750958] xhci_hcd 0000:01:00.0: Vendor specific event TRB type = 48
[ 215.750960] xhci_hcd 0000:01:00.0: NEC firmware version 30.25
[ 215.750962] xhci_hcd 0000:01:00.0: Command ring deq = 0x3781e010 (DMA)
When we resume, the command ring dequeue pointer to be written should have
been 0x3781e010. Instead, it's 0x3781e000:
[ 235.557846] xhci_hcd 0000:01:00.0: // Setting command ring address to 0x3781e001
[ 235.557848] xhci_hcd 0000:01:00.0: `MEM_WRITE_DWORD(3'b000, 64'hffffc900100bc038, 64'h3781e001, 4'hf);
[ 235.557850] xhci_hcd 0000:01:00.0: `MEM_WRITE_DWORD(3'b000, 32'hffffc900100bc020, 32'h204, 4'hf);
[ 235.557866] usb usb9: root hub lost power or was reset
(I can't see the results of this bug because the xHCI restore always fails
on this box, and the xHCI driver re-allocates everything.)
The fix is to zero the command ring and put the software and hardware
enqueue and dequeue pointer back to the beginning of the ring. We do this
before the system suspends, to be paranoid and prevent the BIOS from
starting the host without clearing the command ring pointer, which might
cause the host to muck with stale memory. (The pointer isn't required to
be in the suspend power well, but it could be.) The command ring pointer
is set again after the host resumes.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Andiry Xu <andiry.xu@amd.com>
* 'usb-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (28 commits)
Revert "USB: xhci: Use GFP_ATOMIC under spin_lock"
USB: ohci-jz4740: Fix spelling in MODULE_ALIAS
UWB: Return UWB_RSV_ALLOC_NOT_FOUND rather than crashing on NULL dereference if kzalloc fails
usb: core: fix information leak to userland
usb: misc: iowarrior: fix information leak to userland
usb: misc: sisusbvga: fix information leak to userland
usb: subtle increased memory usage in u_serial
USB: option: fix when the driver is loaded incorrectly for some Huawei devices.
USB: xhci: Use GFP_ATOMIC under spin_lock
usb: gadget: goku_udc: add registered flag bit, fixing build
USB: ehci/mxc: compile fix
USB: Fix FSL USB driver on non Open Firmware systems
USB: the development of the usb tree is now in git
usb: musb: fail unaligned DMA transfers on v1.8 and above
USB: ftdi_sio: add device IDs for Milkymist One JTAG/serial
usb.h: fix ioctl kernel-doc info
usb: musb: gadget: kill duplicate code in musb_gadget_queue()
usb: musb: Fix handling of spurious SESSREQ
usb: musb: fix kernel oops when loading musb_hdrc module for the 2nd time
USB: musb: blackfin: push clkin value to platform resources
...
USB2.0 spec 9.6.6 says: For all endpoints, bit 10..0 specify the maximum
packet size(in bytes).
So the wMaxPacketSize mask should be 0x7ff rather than 0x3ff.
This patch should be queued for the stable tree. The bug in
xhci_endpoint_init() was present as far back as 2.6.31, and the bug in
xhci_get_max_esit_payload() was present when the function was introduced
in 2.6.34.
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
Jiri Slaby reports spinlock is held while calling kmalloc(GFP_KERNEL)
and request_irq() in xhci_resume().
Release the spinlock when setup interrupt.
Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
If the xHCI host controller shares an interrupt line with another device,
the xHCI driver needs to check if the interrupt was generated by its
hardware. Unfortunately, the user will see a ton of "Spurious interrupt."
lines if the other hardware interrupts often. Lawrence found his dmesg
output cluttered with this output when the xHCI host shared an interrupt
with his i915 hardware.
Remove the warning, as sharing an interrupt is a normal thing.
This should be applied to the 2.6.36 stable tree.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: Lawrence Rust <lvr@softsystem.co.uk>
Cc: stable@kernel.org
This reverts commit ef821ae70f.
The correct thing to do is to drop the spinlock, not change
the GFP flag here.
Thanks to Sarah for pointing out I shouldn't have taken this patch in
the first place.
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Structure usbdevfs_connectinfo is copied to userland with padding byted
after "slow" field uninitialized. It leads to leaking of contents of
kernel stack memory.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Structure iowarrior_info is copied to userland with padding byted
between "serial" and "revision" fields uninitialized. It leads to
leaking of contents of kernel stack memory.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: stable <stable@kernel.org>
Acked-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Structure sisusb_info is copied to userland with "sisusb_reserved" field
uninitialized. It leads to leaking of contents of kernel stack memory.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
OK, the USB gadget serial driver actually has a couple of problems. On
gs_open(), it always allocates and queues an additional QUEUE_SIZE (16)
worth of requests, so with a loop like this:
i=1 ; while echo $i > /dev/ttyGS0 ; do let i++ ; done
eventually we run into OOM (Out of Memory).
Technically, it is not a leak as everything gets freed up when the USB
connection is broken, but not on gs_close().
With a USB device/gadget controller driver that has limited resources
(e.g., Marvell has a this MAX_XDS_FOR_TR_CALLS of 64 for transmit and
receive), so even after 4
stty -F /dev/ttyGS0
we cannot transmit anymore. We can still receive (not necessarily
reliably) as now we have 16 * 4 = 64 descriptors/buffers ready, but the
device is otherwise not usable.
Signed-off-by: Jim Sung <jsung@syncadence.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>