linux-kernel - Re: [PATCH V9 1/2] ACPI, PCI, irq: remove interrupt count restriction

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <2131424.aXhRMSo6AO@vostro.rjw.lan>
Date:	Mon, 04 Jan 2016 14:50:57 +0100
From:	"Rafael J. Wysocki" <rjw@...ysocki.net>
To:	Andy Shevchenko <andy.shevchenko@...il.com>
Cc:	Sinan Kaya <okaya@...eaurora.org>,
	Christopher Covington <cov@...eaurora.org>,
	"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
	Timur Tabi <timur@...eaurora.org>, jcm@...hat.com,
	helgaas@...nel.org, Len Brown <lenb@...nel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V9 1/2] ACPI, PCI, irq: remove interrupt count restriction

On Monday, January 04, 2016 11:01:05 AM Andy Shevchenko wrote:
> On Fri, Jan 1, 2016 at 2:48 AM, Rafael J. Wysocki <rjw@...ysocki.net> wrote:
> > On Wednesday, December 30, 2015 09:55:35 PM Andy Shevchenko wrote:
> >> On Wed, Dec 30, 2015 at 9:17 PM, Sinan Kaya <okaya@...eaurora.org> wrote:
> >> > On 12/30/2015 8:28 AM, Andy Shevchenko wrote:
> >> >> Yep, I meant not to use an additional variable.
> >> >>
> >> >>> > BTW, I suggest you spend some time around checkpatch for contributions. I could
> >> >>> > have caught most of the issues you are generally concerned before submitting a patch.
> >> >> Is it a question?
> >> >
> >> > It is a request not a question. I hate wasting your time and my time with things that I could
> >> > have fixed before submitting a patch.
> >> >
> >> > I ran the checkpatch and it said I'm good to go. But, obviously I'm not.
> >>
> >> Hmm… checkpatch.pl is just a small helper to fix style issues. Here is
> >> just a common sense rule, or kind of Occam's razor: no need to have
> >> more variables then needed if it doesn't improve something really
> >> significantly.
> >
> > That said, compilers optimize things anyway, so using an extra local variable
> > shouldn't matter for the resulting machine code.
> 
> I'm not totally against that, but is the additional variable helpful here?

Well, I guess you can argue both ways.

Surely, the same result can be achieved with fewer lines of code if that's
what you mean, so what about the following change on top of the $subject patch?

---
From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Subject: [PATCH] ACPI / PCI: Simplify acpi_penalize_isa_irq()

acpi_penalize_isa_irq() can be written in fewer lines of code,
so do that.  No functional change.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
---
 drivers/acpi/pci_link.c |   14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

Index: linux-pm/drivers/acpi/pci_link.c
===================================================================
--- linux-pm.orig/drivers/acpi/pci_link.c
+++ linux-pm/drivers/acpi/pci_link.c
@@ -877,17 +877,9 @@ static int __init acpi_irq_penalty_updat
  */
 void acpi_penalize_isa_irq(int irq, int active)
 {
-	int penalty;
-
-	if (irq < 0)
-		return;
-
-	if (active)
-		penalty = PIRQ_PENALTY_ISA_USED;
-	else
-		penalty = PIRQ_PENALTY_PCI_USING;
-
-	acpi_irq_add_penalty(irq, penalty);
+	if (irq >= 0)
+		acpi_irq_add_penalty(irq, active ?
+			PIRQ_PENALTY_ISA_USED : PIRQ_PENALTY_PCI_USING);
 }
 
 bool acpi_isa_irq_available(int irq)

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/