kernel/linux.git/drivers/firewire/ohci.c, branch v6.1.168

firewire: ohci: mask bus reset interrupts between ISR and bottom half

2024-05-17T09:56:05+00:00

[ Upstream commit 752e3c53de0fa3b7d817a83050b6699b8e9c6ec9 ] In the FireWire OHCI interrupt handler, if a bus reset interrupt has occurred, mask bus reset interrupts until bus_reset_work has serviced and cleared the interrupt. Normally, we always leave bus reset interrupts masked. We infer the bus reset from the self-ID interrupt that happens shortly thereafter. A scenario where we unmask bus reset interrupts was introduced in 2008 in a007bb857e0b26f5d8b73c2ff90782d9c0972620: If OHCI_PARAM_DEBUG_BUSRESETS (8) is set in the debug parameter bitmask, we will unmask bus reset interrupts so we can log them. irq_handler logs the bus reset interrupt. However, we can't clear the bus reset event flag in irq_handler, because we won't service the event until later. irq_handler exits with the event flag still set. If the corresponding interrupt is still unmasked, the first bus reset will usually freeze the system due to irq_handler being called again each time it exits. This freeze can be reproduced by loading firewire_ohci with "modprobe firewire_ohci debug=-1" (to enable all debugging output). Apparently there are also some cases where bus_reset_work will get called soon enough to clear the event, and operation will continue normally. This freeze was first reported a few months after a007bb85 was committed, but until now it was never fixed. The debug level could safely be set to -1 through sysfs after the module was loaded, but this would be ineffectual in logging bus reset interrupts since they were only unmasked during initialization. irq_handler will now leave the event flag set but mask bus reset interrupts, so irq_handler won't be called again and there will be no freeze. If OHCI_PARAM_DEBUG_BUSRESETS is enabled, bus_reset_work will unmask the interrupt after servicing the event, so future interrupts will be caught as desired. As a side effect to this change, OHCI_PARAM_DEBUG_BUSRESETS can now be enabled through sysfs in addition to during initial module loading. However, when enabled through sysfs, logging of bus reset interrupts will be effective only starting with the second bus reset, after bus_reset_work has executed. Signed-off-by: Adam Goldman Signed-off-by: Takashi Sakamoto Signed-off-by: Sasha Levin

firewire: ohci: suppress unexpected system reboot in AMD Ryzen machines and ASM108x/VT630x PCIe cards

2024-01-10T16:10:35+00:00

commit ac9184fbb8478dab4a0724b279f94956b69be827 upstream. VIA VT6306/6307/6308 provides PCI interface compliant to 1394 OHCI. When the hardware is combined with Asmedia ASM1083/1085 PCIe-to-PCI bus bridge, it appears that accesses to its 'Isochronous Cycle Timer' register (offset 0xf0 on PCI memory space) often causes unexpected system reboot in any type of AMD Ryzen machine (both 0x17 and 0x19 families). It does not appears in the other type of machine (AMD pre-Ryzen machine, Intel machine, at least), or in the other OHCI 1394 hardware (e.g. Texas Instruments). The issue explicitly appears at a commit dcadfd7f7c74 ("firewire: core: use union for callback of transaction completion") added to v6.5 kernel. It changed 1394 OHCI driver to access to the register every time to dispatch local asynchronous transaction. However, the issue exists in older version of kernel as long as it runs in AMD Ryzen machine, since the access to the register is required to maintain bus time. It is not hard to imagine that users experience the unexpected system reboot when generating bus reset by plugging any devices in, or reading the register by time-aware application programs; e.g. audio sample processing. This commit suppresses the unexpected system reboot in the combination of hardware. It avoids the access itself. As a result, the software stack can not provide the hardware time anymore to unit drivers, userspace applications, and nodes in the same IEEE 1394 bus. It brings apparent disadvantage since time-aware application programs require it, while time-unaware applications are available again; e.g. sbp2. Cc: stable@vger.kernel.org Reported-by: Jiri Slaby Closes: https://bugzilla.suse.com/show_bug.cgi?id=1215436 Reported-by: Mario Limonciello Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217994 Reported-by: Tobias Gruetzmacher Closes: https://sourceforge.net/p/linux1394/mailman/message/58711901/ Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2240973 Closes: https://bugs.launchpad.net/linux/+bug/2043905 Link: https://lore.kernel.org/r/20240102110150.244475-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto Signed-off-by: Greg Kroah-Hartman

firewire: ohci: Use tasklet_disable_in_atomic() where required

2021-03-17T15:34:05+00:00

tasklet_disable() is invoked in several places. Some of them are in atomic context which prevents a conversion of tasklet_disable() to a sleepable function. The atomic callchains are: ar_context_tasklet() ohci_cancel_packet() tasklet_disable() ... ohci_flush_iso_completions() tasklet_disable() The invocation of tasklet_disable() from at_context_flush() is always in preemptible context. Use tasklet_disable_in_atomic() for the two invocations in ohci_cancel_packet() and ohci_flush_iso_completions(). Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20210309084242.616379058@linutronix.de

firewire-ohci: use dma_alloc_pages

2020-09-25T04:20:48+00:00

Use dma_alloc_pages to allocate DMAable pages instead of hoping that the architecture either has GFP_DMA32 or not more than 4G of memory. Signed-off-by: Christoph Hellwig

treewide: Use fallthrough pseudo-keyword

2020-08-23T22:36:59+00:00

Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva

treewide: Remove uninitialized_var() usage

2020-07-16T19:35:15+00:00

Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var$([^$]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe # IB Acked-by: Kalle Valo # wireless drivers Reviewed-by: Chao Yu # erofs Signed-off-by: Kees Cook

firewire: ohci: Replace zero-length array with flexible-array

2020-06-16T04:08:31+00:00

There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva

firewire: ohci: stop using get_seconds() for BUS_TIME

2019-11-13T19:59:33+00:00

The ohci driver uses the get_seconds() function to implement the 32-bit CSR_BUS_TIME register. This was added in 2010 commit a48777e03ad5 ("firewire: add CSR BUS_TIME support"). As get_seconds() returns a 32-bit value (on 32-bit architectures), it seems like a good fit for that register, but it is also deprecated because of the y2038/y2106 overflow problem, and should be replaced throughout the kernel with either ktime_get_real_seconds() or ktime_get_seconds(). I'm using the latter here, which uses monotonic time. This has the advantage of behaving better during concurrent settimeofday() updates or leap second adjustments and won't overflow a 32-bit integer, but the downside of using CLOCK_MONOTONIC instead of CLOCK_REALTIME is that the observed values are not related to external clocks. If we instead need UTC but can live with clock jumps or overflows, then we should use ktime_get_real_seconds() instead, retaining the existing behavior. Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/lkml/20180711124923.1205200-1-arnd@arndb.de/ Reviewed-by: Clemens Ladisch Signed-off-by: Stefan Richter

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

drivers: Remove explicit invocations of mmiowb()

2019-04-08T11:01:02+00:00

mmiowb() is now implied by spin_unlock() on architectures that require it, so there is no reason to call it from driver code. This patch was generated using coccinelle: @mmiowb@ @@ - mmiowb(); and invoked as: $ for d in drivers include/linux/qed sound; do \ spatch --include-headers --sp-file mmiowb.cocci --dir $d --in-place; done NOTE: mmiowb() has only ever guaranteed ordering in conjunction with spin_unlock(). However, pairing each mmiowb() removal in this patch with the corresponding call to spin_unlock() is not at all trivial, so there is a small chance that this change may regress any drivers incorrectly relying on mmiowb() to order MMIO writes between CPUs using lock-free synchronisation. If you've ended up bisecting to this commit, you can reintroduce the mmiowb() calls using wmb() instead, which should restore the old behaviour on all architectures other than some esoteric ia64 systems. Acked-by: Linus Torvalds Signed-off-by: Will Deacon