The Synopsys xHC has an internal TRB cache of size TRB_CACHE_SIZE for
each endpoint. The default value for TRB_CACHE_SIZE is 16 for SS and 8
for HS. The controller loads and updates the TRB cache from the transfer
ring in system memory whenever the driver issues a start transfer or
update transfer command.
For chained TRBs, the Synopsys xHC requires that the total amount of
bytes for all TRBs loaded in the TRB cache be greater than or equal to 1
MPS. Or the chain ends within the TRB cache (with a last TRB).
If this requirement is not met, the controller will not be able to send
or receive a packet and it will hang causing a driver timeout and error.
This can be a problem if a class driver queues SG requests with many
small-buffer entries. The XHCI driver will create a chained TRB for each
entry which may trigger this issue.
This patch adds logic to the XHCI driver to detect and prevent this from
happening.
For every (TRB_CACHE_SIZE - 2), we check the total buffer size of
the SG list and if the last window of (TRB_CACHE_SIZE - 2) SG list length
and we don't make up at least 1 MPS, we create a temporary buffer to
consolidate full SG list into the buffer.
We check at (TRB_CACHE_SIZE - 2) window because it is possible that there
would be a link and/or event data TRB that take up to 2 of the cache
entries.
We discovered this issue with devices on other platforms but have not
yet come across any device that triggers this on Linux. But it could be
a real problem now or in the future. All it takes is N number of small
chained TRBs. And other instances of the Synopsys IP may have smaller
values for the TRB_CACHE_SIZE which would exacerbate the problem.
Signed-off-by: Tejas Joglekar <joglekar@synopsys.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20201208092912.1773650-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver core ignores the return value of struct device_driver::remove
because there is only little that can be done. For the shutdown callback
it's ps3_system_bus_shutdown() which ignores the return value.
To simplify the quest to make struct device_driver::remove return void,
let struct ps3_system_bus_driver::remove return void, too. All users
already unconditionally return 0, this commit makes it obvious that
returning an error code is a bad idea and ensures future users behave
accordingly.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126165950.2554997-2-u.kleine-koenig@pengutronix.de
pm_runtime_get_sync() will increment pm usage at first and it
will resume the device later. We should decrease the usage count
whetever it succeeded or failed(maybe runtime of the device has
error, or device is in inaccessible state, or other error state).
If we do not call put operation to decrease the reference, it will
result in reference leak in xhci_histb_probe. Moreover, this
device cannot enter the idle state and always stay busy or other
non-idle state later. So we fixed it by jumping to error handling
branch.
Fixes: c508f41da0 ("xhci: hisilicon: support HiSilicon STB xHCI host controller")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20201106122221.2304528-1-zhangqilong3@huawei.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Creating debugfs files while loding the spin_lock_irqsave(xhci->lock)
creates a lock dependecy that could possibly deadlock.
Lockdep warns:
=====================================================
WARNING: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected
5.10.0-rc1pdx86+ #8 Not tainted
-----------------------------------------------------
systemd-udevd/386 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
ffffffffb1a94038 (pin_fs_lock){+.+.}-{2:2}, at: simple_pin_fs+0x22/0xa0
and this task is already holding:
ffff9e7b87fbc430 (&xhci->lock){-.-.}-{2:2}, at: xhci_alloc_streams+0x5f9/0x810
which would create a new lock dependency:
(&xhci->lock){-.-.}-{2:2} -> (pin_fs_lock){+.+.}-{2:2}
Create the files a bit later after lock is released.
Fixes: 673d746836 ("usb: xhci: add debugfs support for ep with stream")
CC: Li Jun <jun.li@nxp.com>
Reported-by: Hans de Goede <hdegoede@redhat.com>
Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20201028203124.375344-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The usage of in_interrupt() in drivers is phased out for various reasons.
xhci_set_hc_event_deq() has an !in_interrupt() check which is pointless
because the function is only invoked from xhci_mem_init() which is clearly
task context as it does GFP_KERNEL allocations. Remove it.
xhci_urb_enqueue() prints a debug message if an URB is submitted after the
underlying hardware was suspended. But that warning is only issued when
in_interrupt() is true, which makes no sense. Simply return -ESHUTDOWN and
be done with it.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Link: https://lore.kernel.org/r/20201019101110.148631116@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To show the trb ring of streams, use the exsiting ring files of bulk ep
to show trb ring of one specific stream ID, which stream ID's trb ring
will be shown, is controlled by a new debugfs file stream_id, this is to
avoid to create a large number of dir for every allocate stream IDs,
another debugfs file stream_context_array is created to show all the
allocated stream context array entries.
Signed-off-by: Li Jun <jun.li@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200918131752.16488-11-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure xHC completes the configure endpoint command and xhci driver
sets the ring pointers correctly before we create the user readable
debugfs file.
In theory there was a small gap where a user could have read the
debugfs file and cause a NULL pointer dereference error as ring
pointer was not yet set, in practise we want this change to simplify
the upcoming streams debugfs support.
Fixes: 02b6fdc2a1 ("usb: xhci: Add debugfs interface for xHCI driver")
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200918131752.16488-10-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
controllers with XHCI_AVOID_BEI quirk cause too frequent interrupts
and affect power management.
To avoid interrupting on every isochronous interval the BEI (Block
Event Interrupt) flag is set for all except the last Isoch TRB in a URB.
This lead to event ring filling up in case several isoc URB were
queued and cancelled rapidly, which some controllers didn't
handle well, and thus the XHCI_AVOID_BEI quirk was introduced.
see commit 227a4fd801 ("usb: xhci: apply XHCI_AVOID_BEI quirk to all
Intel xHCI controllers")
With the XHCI_AVOID_BEI quirk each Isoch TRB will trigger an interrupt.
This can cause up to 8000 interrupts per second for isochronous transfers
with HD USB3 cameras, affecting power saving.
The event ring fits 256 events, instead of interrupting on every
isochronous TRB if XHCI_AVOID_BEI is set we make sure at least every
8th Isochronous TRB asserts an interrupt, clearing the event ring.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200918131752.16488-9-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the xhci-plat.c is the platform driver, after the runtime pm is
enabled, the xhci_suspend is called if nothing is connected on
the port. When the system goes to suspend, it will call xhci_suspend again
if USB wakeup is enabled.
Since the runtime suspend wakeup setting is not always the same as
system suspend wakeup setting, eg, at runtime suspend we always need
wakeup if the controller is in low power mode; but at system suspend,
we may not need wakeup. So, we move the judgement after changing
wakeup setting.
[commit message rewording -Mathias]
Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200918131752.16488-8-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The CRC calculation done by genksyms is triggered when the parser hits
EXPORT_SYMBOL*() macros. At this point, genksyms recursively expands the
types of the function parameters, and uses that as the input for the CRC
calculation. In the case of forward-declared structs, the type expands
to 'UNKNOWN'. Following this, it appears that the result of the
expansion of each type is cached somewhere, and seems to be re-used
when/if the same type is seen again for another exported symbol in the
same C file.
Unfortunately, this can cause CRC 'stability' issues when a struct
definition becomes visible in the middle of a C file. For example, let's
assume code with the following pattern:
struct foo;
int bar(struct foo *arg)
{
/* Do work ... */
}
EXPORT_SYMBOL_GPL(bar);
/* This contains struct foo's definition */
#include "foo.h"
int baz(struct foo *arg)
{
/* Do more work ... */
}
EXPORT_SYMBOL_GPL(baz);
Here, baz's CRC will be computed using the expansion of struct foo that
was cached after bar's CRC calculation ('UNKOWN' here). But if
EXPORT_SYMBOL_GPL(bar) is removed from the file (because of e.g. symbol
trimming using CONFIG_TRIM_UNUSED_KSYMS), struct foo will be expanded
late, during baz's CRC calculation, which now has visibility over the
full struct definition, hence resulting in a different CRC for baz.
The proper fix for this certainly is in genksyms, but that will take me
some time to get right. In the meantime, we have seen one occurrence of
this in the ehci-hcd code which hits this problem because of the way it
includes C files halfway through the code together with an unlucky mix
of symbol trimming.
In order to workaround this, move the include done in ehci-hub.c early
in ehci-hcd.c, hence making sure the struct definitions are visible to
the entire file. This improves CRC stability of the ehci-hcd exports
even when symbol trimming is enabled.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Quentin Perret <qperret@google.com>
Link: https://lore.kernel.org/r/20200916171825.3228122-1-qperret@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some integrated OHCI controller hubs do not expose all ports of the hub
to pins on the SoC. In some cases the unconnected ports generate
spurious over-current events. For example the Broadcom 56060/Ranger 2 SoC
contains a nominally 3 port hub but only the first port is wired.
Default behaviour for ohci-platform driver is to use global over-current
protection mode (AKA "ganged"). This leads to the spurious over-current
events affecting all ports in the hub.
We now alter the default to use per-port over-current protection.
This patch results in the following configuration changes depending
on quirks:
- For quirk OHCI_QUIRK_SUPERIO no changes. These systems remain set up
for ganged power switching and no over-current protection.
- For quirk OHCI_QUIRK_AMD756 or OHCI_QUIRK_HUB_POWER power switching
remains at none, while over-current protection is now guaranteed to be
set to per-port rather than the previous behaviour where it was either
none or global over-current protection depending on the value at
function entry.
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Link: https://lore.kernel.org/r/20200910212512.16670-1-hamish.martin@alliedtelesis.co.nz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
