Messages in this thread Patch in this message | | | From | Hans de Goede <> | Subject | [PATCH] genirq: Fix [devm_]irq_alloc_desc returning irq 0 | Date | Mon, 21 Dec 2020 19:56:47 +0100 |
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Since commit a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid"), having a linux-irq with number 0 will trigger a WARN when calling platform_get_irq*() to retrieve that linux-irq.
Since [devm_]irq_alloc_desc allocs 1 single irq and since irq 0 is normally not used, it would return 0 before this commit, triggering that WARN. This happens e.g. on Intel Bay Trail and Cherry Trail devices using the LPE audio engine for HDMI audio:
[ 22.761392] ------------[ cut here ]------------ [ 22.761405] 0 is an invalid IRQ number [ 22.761462] WARNING: CPU: 3 PID: 472 at drivers/base/platform.c:238 platform_get_irq_optional+0x108/0x180 [ 22.761470] Modules linked in: snd_hdmi_lpe_audio(+) ... ... [ 22.762133] Call Trace: [ 22.762158] platform_get_irq+0x17/0x30 [ 22.762182] hdmi_lpe_audio_probe+0x4a/0x6c0 [snd_hdmi_lpe_audio] ... [ 22.762726] ---[ end trace ceece38854223a0b ]---
Change the 'from' parameter passed to __[devm_]irq_alloc_descs() by the [devm_]irq_alloc_desc macros from 0 to 1, so that these macros will no longer return 0.
Cc: Bjorn Helgaas <bhelgaas@google.com> Fixes: a85a6c86c25b ("driver core: platform: Clarify that IRQ 0 is invalid") Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- A quick grep for 'irq_alloc_desc\(' shows only 2 users of irq_alloc_desc(): 1. drivers/gpu/drm/i915/display/intel_lpe_audio.c 2. drivers/sh/intc/virq.c But that might very well be an incomplete list. --- include/linux/irq.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/irq.h b/include/linux/irq.h index c54365309e97..a36d35c25996 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -922,7 +922,7 @@ int __devm_irq_alloc_descs(struct device *dev, int irq, unsigned int from, __irq_alloc_descs(irq, from, cnt, node, THIS_MODULE, NULL) #define irq_alloc_desc(node) \ - irq_alloc_descs(-1, 0, 1, node) + irq_alloc_descs(-1, 1, 1, node) #define irq_alloc_desc_at(at, node) \ irq_alloc_descs(at, at, 1, node) @@ -937,7 +937,7 @@ int __devm_irq_alloc_descs(struct device *dev, int irq, unsigned int from, __devm_irq_alloc_descs(dev, irq, from, cnt, node, THIS_MODULE, NULL) #define devm_irq_alloc_desc(dev, node) \ - devm_irq_alloc_descs(dev, -1, 0, 1, node) + devm_irq_alloc_descs(dev, -1, 1, 1, node) #define devm_irq_alloc_desc_at(dev, at, node) \ devm_irq_alloc_descs(dev, at, at, 1, node) -- 2.28.0
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