linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Ayan Kumar Halder <ayankuma@amd.com>
To: <stefano.stabellini@xilinx.com>, <sstabellini@kernel.org>,
	<julien@xen.org>, <bertrand.marquis@arm.com>,
	<mark.rutland@arm.com>, <maz@kernel.org>,
	<daniel.lezcano@linaro.org>, <tglx@linutronix.de>
Cc: <linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	Ayan Kumar Halder <ayankuma@amd.com>
Subject: [PATCH v1] arm: clocksource: Check if timer is enabled for timer irq
Date: Thu, 11 Aug 2022 10:36:20 +0100	[thread overview]
Message-ID: <20220811093620.16680-1-ayankuma@amd.com> (raw)

Refer ARM DDI 0487G.b, CNTP_CTL_EL0,
ISTATUS, bit [2] - When the value of the ENABLE bit is 1, ISTATUS
indicates whether the timer condition is met.

Thus, one need to check ENABLE bit along with ISTATUS, to confirm
whether the timer condition is met. Further as the doc says,
"When the value of the ENABLE bit is 0, the ISTATUS field is UNKNOWN."

Signed-off-by: Ayan Kumar Halder <ayankuma@amd.com>
---

Please refer to https://lore.kernel.org/all/6cfcd4fa-3afd-1c70-6a70-9df557ee1811@xen.org/T/
for the previous discussion on this issue on xen-devel mailing list.

 drivers/clocksource/arm_arch_timer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 9ab8221ee3c6..96921772814c 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -647,7 +647,7 @@ static __always_inline irqreturn_t timer_handler(const int access,
 	unsigned long ctrl;
 
 	ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL, evt);
-	if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
+	if ((ctrl & ARCH_TIMER_CTRL_IT_STAT) && (ctrl & ARCH_TIMER_CTRL_ENABLE)) {
 		ctrl |= ARCH_TIMER_CTRL_IT_MASK;
 		arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl, evt);
 		evt->event_handler(evt);
-- 
2.17.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2022-08-11  9:38 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-11  9:36 Ayan Kumar Halder [this message]
2022-08-11  9:49 ` [PATCH v1] arm: clocksource: Check if timer is enabled for timer irq Marc Zyngier
2023-05-25 16:03   ` Ayan Kumar Halder
2023-05-25 16:44     ` Marc Zyngier

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220811093620.16680-1-ayankuma@amd.com \
    --to=ayankuma@amd.com \
    --cc=bertrand.marquis@arm.com \
    --cc=daniel.lezcano@linaro.org \
    --cc=julien@xen.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=maz@kernel.org \
    --cc=sstabellini@kernel.org \
    --cc=stefano.stabellini@xilinx.com \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).