Applied "Revert "ASoC: Intel: Skylake: Acquire irq after RIRB allocation"" to the asoc tree

Commit Message

Mark Brown Sept. 13, 2018, 11:39 a.m. UTC

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 <[e-mail]>
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 <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>
---
 sound/soc/intel/skylake/skl.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

Patch

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);