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  1. 06 Aug, 2018 31 commits
  3. 28 Jul, 2018 9 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.4.145 · ac15b2b2
      Greg Kroah-Hartman authored
      ac15b2b2
    • Arnd Bergmann's avatar
      ARM: fix put_user() for gcc-8 · 0ca85fc3
      Arnd Bergmann authored 
      Building kernels before linux-4.7 with gcc-8 results in many build failures
when gcc triggers a check that was meant to catch broken compilers:

/tmp/ccCGMQmS.s:648: Error: .err encountered

According to the discussion in the gcc bugzilla, a local "register
asm()" variable is still supposed to be the correct way to force an
inline assembly to use a particular register, but marking it 'const'
lets the compiler do optimizations that break that, i.e the compiler is
free to treat the variable as either 'const' or 'register' in that case.

Upstream commit 9f73bd8b ("ARM: uaccess: remove put_user() code
duplication") fixed this problem in linux-4.8 as part of a larger change,
but seems a little too big to be backported to 4.4.

Let's take the simplest fix and change only the one broken line in the
same way as newer kernels.
Suggested-by: default avatarBernd Edlinger <bernd.edlinger@hotmail.de>
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85745
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86673Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0ca85fc3
    • Arnd Bergmann's avatar
      turn off -Wattribute-alias · d41d0fe3
      Arnd Bergmann authored 
      Starting with gcc-8.1, we get a warning about all system call definitions,
which use an alias between functions with incompatible prototypes, e.g.:

In file included from ../mm/process_vm_access.c:19:
../include/linux/syscalls.h:211:18: warning: 'sys_process_vm_readv' alias between functions of incompatible types 'long int(pid_t,  const struct iovec *, long unsigned int,  const struct iovec *, long unsigned int,  long unsigned int)' {aka 'long int(int,  const struct iovec *, long unsigned int,  const struct iovec *, long unsigned int,  long unsigned int)'} and 'long int(long int,  long int,  long int,  long int,  long int,  long int)' [-Wattribute-alias]
  asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \
                  ^~~
../include/linux/syscalls.h:207:2: note: in expansion of macro '__SYSCALL_DEFINEx'
  __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
  ^~~~~~~~~~~~~~~~~
../include/linux/syscalls.h:201:36: note: in expansion of macro 'SYSCALL_DEFINEx'
 #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
                                    ^~~~~~~~~~~~~~~
../mm/process_vm_access.c:300:1: note: in expansion of macro 'SYSCALL_DEFINE6'
 SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec,
 ^~~~~~~~~~~~~~~
../include/linux/syscalls.h:215:18: note: aliased declaration here
  asmlinkage long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \
                  ^~~
../include/linux/syscalls.h:207:2: note: in expansion of macro '__SYSCALL_DEFINEx'
  __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
  ^~~~~~~~~~~~~~~~~
../include/linux/syscalls.h:201:36: note: in expansion of macro 'SYSCALL_DEFINEx'
 #define SYSCALL_DEFINE6(name, ...) SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
                                    ^~~~~~~~~~~~~~~
../mm/process_vm_access.c:300:1: note: in expansion of macro 'SYSCALL_DEFINE6'
 SYSCALL_DEFINE6(process_vm_readv, pid_t, pid, const struct iovec __user *, lvec,

This is really noisy and does not indicate a real problem. In the latest
mainline kernel, this was addressed by commit bee20031 ("disable
-Wattribute-alias warning for SYSCALL_DEFINEx()"), which seems too invasive
to backport.

This takes a much simpler approach and just disables the warning across the
kernel.
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d41d0fe3
    • Anssi Hannula's avatar
      can: xilinx_can: fix RX overflow interrupt not being enabled · 264dc158
      Anssi Hannula authored 
      commit 83997997 upstream.

RX overflow interrupt (RXOFLW) is disabled even though xcan_interrupt()
processes it. This means that an RX overflow interrupt will only be
processed when another interrupt gets asserted (e.g. for RX/TX).

Fix that by enabling the RXOFLW interrupt.

Fixes: b1201e44 ("can: xilinx CAN controller support")
Signed-off-by: default avatarAnssi Hannula <anssi.hannula@bitwise.fi>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      264dc158
    • Anssi Hannula's avatar
      can: xilinx_can: fix incorrect clear of non-processed interrupts · f7efacee
      Anssi Hannula authored 
      commit 2f4f0f33 upstream.

xcan_interrupt() clears ERROR|RXOFLV|BSOFF|ARBLST interrupts if any of
them is asserted. This does not take into account that some of them
could have been asserted between interrupt status read and interrupt
clear, therefore clearing them without handling them.

Fix the code to only clear those interrupts that it knows are asserted
and therefore going to be processed in xcan_err_interrupt().

Fixes: b1201e44 ("can: xilinx CAN controller support")
Signed-off-by: default avatarAnssi Hannula <anssi.hannula@bitwise.fi>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f7efacee
    • Anssi Hannula's avatar
      can: xilinx_can: keep only 1-2 frames in TX FIFO to fix TX accounting · e5df9264
      Anssi Hannula authored 
      commit 620050d9 upstream.

The xilinx_can driver assumes that the TXOK interrupt only clears after
it has been acknowledged as many times as there have been successfully
sent frames.

However, the documentation does not mention such behavior, instead
saying just that the interrupt is cleared when the clear bit is set.

Similarly, testing seems to also suggest that it is immediately cleared
regardless of the amount of frames having been sent. Performing some
heavy TX load and then going back to idle has the tx_head drifting
further away from tx_tail over time, steadily reducing the amount of
frames the driver keeps in the TX FIFO (but not to zero, as the TXOK
interrupt always frees up space for 1 frame from the driver's
perspective, so frames continue to be sent) and delaying the local echo
frames.

The TX FIFO tracking is also otherwise buggy as it does not account for
TX FIFO being cleared after software resets, causing
  BUG!, TX FIFO full when queue awake!
messages to be output.

There does not seem to be any way to accurately track the state of the
TX FIFO for local echo support while using the full TX FIFO.

The Zynq version of the HW (but not the soft-AXI version) has watermark
programming support and with it an additional TX-FIFO-empty interrupt
bit.

Modify the driver to only put 1 frame into TX FIFO at a time on soft-AXI
and 2 frames at a time on Zynq. On Zynq the TXFEMP interrupt bit is used
to detect whether 1 or 2 frames have been sent at interrupt processing
time.

Tested with the integrated CAN on Zynq-7000 SoC. The 1-frame-FIFO mode
was also tested.

An alternative way to solve this would be to drop local echo support but
keep using the full TX FIFO.

v2: Add FIFO space check before TX queue wake with locking to
synchronize with queue stop. This avoids waking the queue when xmit()
had just filled it.

v3: Keep local echo support and reduce the amount of frames in FIFO
instead as suggested by Marc Kleine-Budde.

Fixes: b1201e44 ("can: xilinx CAN controller support")
Signed-off-by: default avatarAnssi Hannula <anssi.hannula@bitwise.fi>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e5df9264
    • Anssi Hannula's avatar
      can: xilinx_can: fix device dropping off bus on RX overrun · d7dec444
      Anssi Hannula authored 
      commit 2574fe54 upstream.

The xilinx_can driver performs a software reset when an RX overrun is
detected. This causes the device to enter Configuration mode where no
messages are received or transmitted.

The documentation does not mention any need to perform a reset on an RX
overrun, and testing by inducing an RX overflow also indicated that the
device continues to work just fine without a reset.

Remove the software reset.

Tested with the integrated CAN on Zynq-7000 SoC.

Fixes: b1201e44 ("can: xilinx CAN controller support")
Signed-off-by: default avatarAnssi Hannula <anssi.hannula@bitwise.fi>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d7dec444
    • Anssi Hannula's avatar
      can: xilinx_can: fix recovery from error states not being propagated · 7e572a17
      Anssi Hannula authored 
      commit 877e0b75 upstream.

The xilinx_can driver contains no mechanism for propagating recovery
from CAN_STATE_ERROR_WARNING and CAN_STATE_ERROR_PASSIVE.

Add such a mechanism by factoring the handling of
XCAN_STATE_ERROR_PASSIVE and XCAN_STATE_ERROR_WARNING out of
xcan_err_interrupt and checking for recovery after RX and TX if the
interface is in one of those states.

Tested with the integrated CAN on Zynq-7000 SoC.

Fixes: b1201e44 ("can: xilinx CAN controller support")
Signed-off-by: default avatarAnssi Hannula <anssi.hannula@bitwise.fi>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7e572a17
    • Anssi Hannula's avatar
      can: xilinx_can: fix RX loop if RXNEMP is asserted without RXOK · e4c55764
      Anssi Hannula authored 
      commit 32852c56 upstream.

If the device gets into a state where RXNEMP (RX FIFO not empty)
interrupt is asserted without RXOK (new frame received successfully)
interrupt being asserted, xcan_rx_poll() will continue to try to clear
RXNEMP without actually reading frames from RX FIFO. If the RX FIFO is
not empty, the interrupt will not be cleared and napi_schedule() will
just be called again.

This situation can occur when:

(a) xcan_rx() returns without reading RX FIFO due to an error condition.
The code tries to clear both RXOK and RXNEMP but RXNEMP will not clear
due to a frame still being in the FIFO. The frame will never be read
from the FIFO as RXOK is no longer set.

(b) A frame is received between xcan_rx_poll() reading interrupt status
and clearing RXOK. RXOK will be cleared, but RXNEMP will again remain
set as the new message is still in the FIFO.

I'm able to trigger case (b) by flooding the bus with frames under load.

There does not seem to be any benefit in using both RXNEMP and RXOK in
the way the driver does, and the polling example in the reference manual
(UG585 v1.10 18.3.7 Read Messages from RxFIFO) also says that either
RXOK or RXNEMP can be used for detecting incoming messages.

Fix the issue and simplify the RX processing by only using RXNEMP
without RXOK.

Tested with the integrated CAN on Zynq-7000 SoC.

Fixes: b1201e44 ("can: xilinx CAN controller support")
Signed-off-by: default avatarAnssi Hannula <anssi.hannula@bitwise.fi>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e4c55764
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