In general it is wise to clear interrupts before processing them. If
you don't do that, you can get:
1. Interrupt happens
2. You look at system state and process interrupt
3. A new interrupt happens
4. You clear interrupt without processing it.
This patch was actually a first attempt to fix missing device insertions
as described in (usb: dwc2: host: Fix missing device insertions) and it
did solve some of the signal bouncing problems but not all of
them (which is why I submitted the other patch). Specifically, this
patch itself would sometimes change:
1. hardware sees connect
2. hardware sees disconnect
3. hardware sees connect
4. dwc2_port_intr() - clears connect interrupt
5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect()
...to:
1. hardware sees connect
2. hardware sees disconnect
3. dwc2_port_intr() - clears connect interrupt
4. hardware sees connect
5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect()
...but with different timing then sometimes we'd still miss cable
insertions.
In any case, though this patch doesn't fix any (known) problems, it
still seems wise as a general policy to clear interrupt before handling
them.
Note that for dwc2_handle_usb_port_intr(), instead of moving the clear
of PRTINT to the beginning of the function we remove it completely. The
only way to clear PRTINT is to clear the sources that set it in the
first place.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
If you've got your interrupt signals bouncing a bit as you insert your
USB device, you might end up in a state when the device is connected but
the driver doesn't know it.
Specifically, the observed order is:
1. hardware sees connect
2. hardware sees disconnect
3. hardware sees connect
4. dwc2_port_intr() - clears connect interrupt
5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect()
Now you'll be stuck with the cable plugged in and no further interrupts
coming in but the driver will think we're disconnected.
We'll fix this by checking for the missing connect interrupt and
re-connecting after the disconnect is posted. We don't skip the
disconnect because if there is a transitory disconnect we really want to
de-enumerate and re-enumerate.
Notes:
1. As part of this change we add a "force" parameter to
dwc2_hcd_disconnect() so that when we're unloading the module we
avoid the new behavior. The need for this was pointed out by John
Youn.
2. The bit of code needed at the end of dwc2_hcd_disconnect() is
exactly the same bit of code from dwc2_port_intr(). To avoid
duplication, we refactor that code out into a new function
dwc2_hcd_connect().
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: John Youn <johnyoun@synopsys.com>
Tested-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
As descriptor dma mode does not support split transfers, it can't be
enabled for high speed devices. Add a core parameter to enable it for
full speed devices.
Ensure frame list and descriptor list are correctly freed during
disconnect.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Mian Yousaf Kaukab <yousaf.kaukab@intel.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
While plugging / unplugging on a DWC2 host port with "slub_debug=FZPUA"
enabled, I found a crash that was quite obviously a use after free.
It appears that in some cases when we handle the various sub-cases of
HCINT we may end up freeing the QTD. If there is more than one bit set
in HCINT we may then end up continuing to use the QTD, which is bad.
Let's be paranoid and check for this after each sub-case. This should
be safe since we officially have the "hsotg->lock" (it was grabbed in
dwc2_handle_hcd_intr).
The specific crash I found was:
Unable to handle kernel paging request at virtual address 6b6b6b9f
At the time of the crash, the kernel reported:
(dwc2_hc_nak_intr+0x5c/0x198)
(dwc2_handle_hcd_intr+0xa84/0xbf8)
(_dwc2_hcd_irq+0x1c/0x20)
(usb_hcd_irq+0x34/0x48)
Popping into kgdb found that "*qtd" was filled with "0x6b", AKA qtd had
been freed and filled with slub_debug poison.
kgdb gave a little better stack crawl:
0 dwc2_hc_nak_intr (hsotg=hsotg@entry=0xec42e058,
chan=chan@entry=0xec546dc0, chnum=chnum@entry=4,
qtd=qtd@entry=0xec679600) at drivers/usb/dwc2/hcd_intr.c:1237
1 dwc2_hc_n_intr (chnum=4, hsotg=0xec42e058) at
drivers/usb/dwc2/hcd_intr.c:2041
2 dwc2_hc_intr (hsotg=0xec42e058) at drivers/usb/dwc2/hcd_intr.c:2078
3 dwc2_handle_hcd_intr (hsotg=0xec42e058) at
drivers/usb/dwc2/hcd_intr.c:2128
4 _dwc2_hcd_irq (hcd=<optimized out>) at drivers/usb/dwc2/hcd.c:2837
5 usb_hcd_irq (irq=<optimized out>, __hcd=<optimized out>) at
drivers/usb/core/hcd.c:2353
Popping up to frame #1 (dwc2_hc_n_intr) found:
(gdb) print /x hcint
$12 = 0x12
AKA:
#define HCINTMSK_CHHLTD (1 << 1)
#define HCINTMSK_NAK (1 << 4)
Further debugging found that by simulating receiving those two
interrupts at the same time it was trivial to replicate the
use-after-free. See <http://crosreview.com/305712> for a patch and
instructions. This lead to getting the following stack crawl of the
actual free:
0 arch_kgdb_breakpoint () at arch/arm/include/asm/outercache.h:103
1 kgdb_breakpoint () at kernel/debug/debug_core.c:1054
2 dwc2_hcd_qtd_unlink_and_free (hsotg=<optimized out>, qh=<optimized
out>, qtd=0xe4479a00) at drivers/usb/dwc2/hcd.h:488
3 dwc2_deactivate_qh (free_qtd=<optimized out>, qh=0xe5efa280,
hsotg=0xed424618) at drivers/usb/dwc2/hcd_intr.c:671
4 dwc2_release_channel (hsotg=hsotg@entry=0xed424618,
chan=chan@entry=0xed5be000, qtd=<optimized out>,
halt_status=<optimized out>) at drivers/usb/dwc2/hcd_intr.c:742
5 dwc2_halt_channel (hsotg=0xed424618, chan=0xed5be000, qtd=<optimized
out>, halt_status=<optimized out>) at
drivers/usb/dwc2/hcd_intr.c:804
6 dwc2_complete_non_periodic_xfer (chnum=<optimized out>,
halt_status=<optimized out>, qtd=<optimized out>, chan=<optimized
out>, hsotg=<optimized out>) at drivers/usb/dwc2/hcd_intr.c:889
7 dwc2_hc_xfercomp_intr (hsotg=hsotg@entry=0xed424618,
chan=chan@entry=0xed5be000, chnum=chnum@entry=6,
qtd=qtd@entry=0xe4479a00) at drivers/usb/dwc2/hcd_intr.c:1065
8 dwc2_hc_chhltd_intr_dma (qtd=0xe4479a00, chnum=6, chan=0xed5be000,
hsotg=0xed424618) at drivers/usb/dwc2/hcd_intr.c:1823
9 dwc2_hc_chhltd_intr (qtd=0xe4479a00, chnum=6, chan=0xed5be000,
hsotg=0xed424618) at drivers/usb/dwc2/hcd_intr.c:1944
10 dwc2_hc_n_intr (chnum=6, hsotg=0xed424618) at
drivers/usb/dwc2/hcd_intr.c:2052
11 dwc2_hc_intr (hsotg=0xed424618) at drivers/usb/dwc2/hcd_intr.c:2097
12 dwc2_handle_hcd_intr (hsotg=0xed424618) at
drivers/usb/dwc2/hcd_intr.c:2147
13 _dwc2_hcd_irq (hcd=<optimized out>) at drivers/usb/dwc2/hcd.c:2837
14 usb_hcd_irq (irq=<optimized out>, __hcd=<optimized out>) at
drivers/usb/core/hcd.c:2353
Though we could add specific code to handle this case, adding the
general purpose code to check for all cases where qtd might be freed
seemed safer.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
This patch switches calls to readl/writel to their
dwc2_readl/dwc2_writel equivalents which preserve platform endianness.
This patch is necessary to access dwc2 registers correctly on big-endian
systems such as the mips based SoCs made by Lantiq. Then dwc2 can be
used to replace ifx-hcd driver for Lantiq platforms found e.g. in
OpenWrt.
The patch was autogenerated with the following commands:
$EDITOR core.h
sed -i "s/\<readl\>/dwc2_readl/g" *.c hcd.h hw.h
sed -i "s/\<writel\>/dwc2_writel/g" *.c hcd.h hw.h
Some files were then hand-edited to fix checkpatch.pl warnings about
too long lines.
Signed-off-by: Antti Seppälä <a.seppala@gmail.com>
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
dwc2_hc_nak_intr could be called with a NULL qtd.
Ensure qtd exists before dereferencing it to avoid kernel panic.
This happens when using usb to ethernet adapter.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Align buffer must be allocated using kmalloc since irqs are disabled.
Coherency is handled through dma_map_single which can be used with irqs
disabled.
Reviewed-by: Julius Werner <jwerner@chromium.org>
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Once hub is runtime suspended, dwc2 must resume it
on port connect event.
Else, roothub will stay in suspended state and will
not resume transfers.
Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
The driver's handling of DMA buffers for non-aligned transfers
was kind of nuts. For IN transfers, it left the URB DMA buffer
mapped until the transfer completed, then synced it, copied the
data from the bounce buffer, then synced it again.
Instead of that, just call usb_hcd_unmap_urb_for_dma() to unmap
the buffer before starting the transfer. Then no syncing is
required when doing the copy. This should also allow handling of
other types of mappings besides just dma_map_single() ones.
Also reduce the size of the bounce buffer allocation for Isoc
endpoints to 3K, since that's the largest possible transfer size.
Tested on Raspberry Pi and Altera SOCFPGA.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
I'm seeing problems with a d-link dwcl-g122 wifi dongle that
someone sent me. There are reports of other wifi dongles with the
same/similar problem. The devices appear to be NAKing to the point
of confusing the dwc2 driver completely.
The attached patch helps with my d-link dwl-g122 - it's adapted
from the Raspberry Pi dwc_otg driver, which is a modified version
of the Synopsys vendor driver. The error recovery is still valid
after the patch, I think.
Cc: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Nick Hudson <skrll@netbsd.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In a couple of places, we were checking qtd->urb for NULL after
we had already dereferenced it. Fix this by moving the check to
before the dereference.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The DWC2 driver should now be in good enough shape to move out of
staging. I have stress tested it overnight on RPI running mass
storage and Ethernet transfers in parallel, and for several days
on our proprietary PCI-based platform.
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
