Hi, Rafael > From: Rafael J. Wysocki [mailto:rjw@xxxxxxxxxxxxx] > Subject: Re: [PATCH] ACPI / EC: Fix a regression by reducing parallel _Qxx > evaluations > > On Friday, July 29, 2016 03:58:20 AM Zheng, Lv wrote: > > Hi, Rafael > > > > > From: Zheng, Lv > > > Subject: [PATCH] ACPI / EC: Fix a regression by reducing parallel _Qxx > > > evaluations > > > > > > A regression is caused by the following commit: > > > Commit: 02b771b64b73226052d6e731a0987db3b47281e9 > > > Subject: ACPI / EC: Fix an issue caused by the serialized _Qxx > evaluations > > > In this commit, using system workqueue causes that the maximum > parallel > > > executions of _Qxx can exceed 255. This violates the method > reentrancy > > > limit in ACPICA and generates the following error log: > > > ACPI Error: Method reached maximum reentrancy limit (255) > > > (20150818/dsmethod-341) > > > > > > This patch creates a seperate workqueue and limits the number of > parallel > > > _Qxx evaluations down to a configurable value (can be tuned against > > > number > > > of online CPUs). > > > > > > Since EC events are handled after driver probe, we can create the > > > workqueue > > > in acpi_ec_init(). > > > > > > Fixes: 02b771b64b73 (ACPI / EC: Fix an issue caused by the serialized > _Qxx > > > evaluations) > > > Cc: <stable@xxxxxxxxxxxxxxx> # 4.3+ > > > Reported-and-tested-by: Helen Buus <ubuntu@xxxxxxxxx> > > [Lv Zheng] > > I'm sorry that I forgot to mention the bug link. > > It's actually recorded in kernel Bugzilla. > > The bug can be found here: > > Link: https://bugzilla.kernel.org/show_bug.cgi?id=135691 > > Hope you can help to add this useful information if this patch is > acceptable. > > I did that, but due to the problem reported against this patch > (https://patchwork.kernel.org/patch/9252645/), I'm going to drop it from > linux-next and I'll be waiting for an update with that problem addressed. [Lv Zheng] OK, I'll re-send an update of this patch. Sorry for the problem. Thanks Lv ��.n��������+%������w��{.n�����{�����ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
