The patch

Revert "ASoC: Intel: Skylake: Acquire irq after RIRB allocation"

has been applied to the asoc tree at

https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git

All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying to this mail.

Thanks, Mark

From 542cedec53c9e8b73f3f05bf8468823598c50489 Mon Sep 17 00:00:00 2001

From: Yu Zhao yuzhao@google.com Date: Tue, 11 Sep 2018 15:12:46 -0600 Subject: [PATCH] Revert "ASoC: Intel: Skylake: Acquire irq after RIRB allocation"

This reverts commit 12eeeb4f4733bbc4481d01df35933fc15beb8b19.

The patch doesn't fix accessing memory with null pointer in skl_interrupt().

There are two problems: 1) skl_init_chip() is called twice, before and after dma buffer is allocate. The first call sets bus->chip_init which prevents the second from initializing bus->corb.buf and rirb.buf from bus->rb.area. 2) snd_hdac_bus_init_chip() enables interrupt before snd_hdac_bus_init_cmd_io() initializing dma buffers. There is a small window which skl_interrupt() can be called if irq has been acquired. If so, it crashes when using null dma buffer pointers.

Will fix the problems in the following patches. Also attaching the crash for future reference.

[ 16.949148] general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI <snipped> [ 16.950903] Call Trace: [ 16.950906] <IRQ> [ 16.950918] skl_interrupt+0x19e/0x2d6 [snd_soc_skl] [ 16.950926] ? dma_supported+0xb5/0xb5 [snd_soc_skl] [ 16.950933] __handle_irq_event_percpu+0x27a/0x6c8 [ 16.950937] ? __irq_wake_thread+0x1d1/0x1d1 [ 16.950942] ? __do_softirq+0x57a/0x69e [ 16.950944] handle_irq_event_percpu+0x95/0x1ba [ 16.950948] ? _raw_spin_unlock+0x65/0xdc [ 16.950951] ? __handle_irq_event_percpu+0x6c8/0x6c8 [ 16.950953] ? _raw_spin_unlock+0x65/0xdc [ 16.950957] ? time_cpufreq_notifier+0x483/0x483 [ 16.950959] handle_irq_event+0x89/0x123 [ 16.950962] handle_fasteoi_irq+0x16f/0x425 [ 16.950965] handle_irq+0x1fe/0x28e [ 16.950969] do_IRQ+0x6e/0x12e [ 16.950972] common_interrupt+0x7a/0x7a [ 16.950974] </IRQ> <snipped> [ 16.951031] RIP: snd_hdac_bus_update_rirb+0x19b/0x4cf [snd_hda_core] RSP: ffff88015c807c08 [ 16.951036] ---[ end trace 58bf9ece1775bc92 ]---

Fixes: 2eeeb4f4733b ("ASoC: Intel: Skylake: Acquire irq after RIRB allocation") Signed-off-by: Yu Zhao yuzhao@google.com Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/intel/skylake/skl.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/sound/soc/intel/skylake/skl.c b/sound/soc/intel/skylake/skl.c index cf09721ca13e..dce649485649 100644 --- a/sound/soc/intel/skylake/skl.c +++ b/sound/soc/intel/skylake/skl.c @@ -838,7 +838,11 @@ static int skl_first_init(struct hdac_bus *bus)

snd_hdac_bus_parse_capabilities(bus);

+ if (skl_acquire_irq(bus, 0) < 0) + return -EBUSY; + pci_set_master(pci); + synchronize_irq(bus->irq);

gcap = snd_hdac_chip_readw(bus, GCAP); dev_dbg(bus->dev, "chipset global capabilities = 0x%x\n", gcap); @@ -871,12 +875,6 @@ static int skl_first_init(struct hdac_bus *bus) if (err < 0) return err;

- err = skl_acquire_irq(bus, 0); - if (err < 0) - return err; - - synchronize_irq(bus->irq); - /* initialize chip */ skl_init_pci(skl);