From: Guenter Roeck <linux@roeck-us.net>
To: "Alice Guo (OSS)" <alice.guo@oss.nxp.com>
Cc: wim@linux-watchdog.org, shawnguo@kernel.org,
s.hauer@pengutronix.de, festevam@gmail.com,
kernel@pengutronix.de, linux-imx@nxp.com,
linux-watchdog@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/7] watchdog: imx7ulp_wdt: Check CMD32EN in wdog init
Date: Mon, 22 Aug 2022 07:05:57 -0700 [thread overview]
Message-ID: <20220822140557.GB4087281@roeck-us.net> (raw)
In-Reply-To: <20220816043643.26569-4-alice.guo@oss.nxp.com>
On Tue, Aug 16, 2022 at 12:36:39PM +0800, Alice Guo (OSS) wrote:
> From: Ye Li <ye.li@nxp.com>
>
> When bootloader has enabled the CMD32EN bit, switch to use 32bits
> unlock command to unlock the CS register. Using 32bits command will
> help on avoiding 16 bus cycle window violation for two 16 bits
> commands.
>
> Signed-off-by: Ye Li <ye.li@nxp.com>
> Signed-off-by: Alice Guo <alice.guo@nxp.com>
> Reviewed-by: Jacky Bai <ping.bai@nxp.com>
> Acked-by: Jason Liu <jason.hui.liu@nxp.com>
> ---
> drivers/watchdog/imx7ulp_wdt.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
> index b8ac0cb04d2f..a0f6b8cea78f 100644
> --- a/drivers/watchdog/imx7ulp_wdt.c
> +++ b/drivers/watchdog/imx7ulp_wdt.c
> @@ -180,11 +180,16 @@ static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
>
> local_irq_disable();
>
> - mb();
> - /* unlock the wdog for reconfiguration */
> - writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
> - writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
> - mb();
> + val = readl(base + WDOG_CS);
> + if (val & WDOG_CS_CMD32EN) {
> + writel(UNLOCK, base + WDOG_CNT);
> + } else {
> + mb();
> + /* unlock the wdog for reconfiguration */
> + writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
> + writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
> + mb();
Now this is intermixing writel() with writel_relaxed(), making
the code all but impossible to understand.
Guenter
> + }
>
> ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK);
> if (ret)
> --
> 2.17.1
>
next prev parent reply other threads:[~2022-08-22 14:06 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-16 4:36 [PATCH 0/7] watchdog: imx7ulp_wdt: update i.MX7ULP WDOG timer driver Alice Guo (OSS)
2022-08-16 4:36 ` [PATCH 1/7] watchdog: imx7ulp: Move suspend/resume to noirq phase Alice Guo (OSS)
2022-08-16 4:36 ` [PATCH 2/7] watchdog: imx7ulp: Add explict memory barrier for unlock sequence Alice Guo (OSS)
2022-08-16 6:23 ` Marco Felsch
2022-08-22 7:49 ` Alice Guo (OSS)
2022-08-22 8:00 ` Marco Felsch
2022-08-22 14:03 ` Guenter Roeck
2022-08-23 5:38 ` Alice Guo (OSS)
2022-08-23 9:10 ` Marco Felsch
2022-08-23 12:02 ` Guenter Roeck
2022-08-24 6:24 ` Alice Guo (OSS)
2022-08-24 8:03 ` Marco Felsch
2022-08-24 8:40 ` Alice Guo (OSS)
2022-08-24 9:06 ` Marco Felsch
2022-08-24 10:05 ` Alice Guo (OSS)
2022-08-25 7:50 ` Marco Felsch
2022-08-25 8:08 ` Alice Guo (OSS)
2022-08-25 9:01 ` Marco Felsch
2022-08-25 10:11 ` Alice Guo (OSS)
2022-08-16 4:36 ` [PATCH 3/7] watchdog: imx7ulp_wdt: Check CMD32EN in wdog init Alice Guo (OSS)
2022-08-22 14:05 ` Guenter Roeck [this message]
2022-08-23 5:46 ` Alice Guo (OSS)
2022-08-23 12:05 ` Guenter Roeck
2022-08-16 4:36 ` [PATCH 4/7] watchdog: imx7ulp_wdt: Fix RCS timeout issue Alice Guo (OSS)
2022-08-22 14:09 ` Guenter Roeck
2022-08-23 5:59 ` Alice Guo (OSS)
2022-08-23 12:06 ` Guenter Roeck
2022-08-24 6:44 ` Alice Guo (OSS)
2022-08-16 4:36 ` [PATCH 5/7] watchdog: imx7ulp_wdt: Handle wdog reconfigure failure Alice Guo (OSS)
2022-08-16 4:36 ` [PATCH 6/7] watchdog: imx7ulp_wdt: init wdog when it was active Alice Guo (OSS)
2022-08-16 4:36 ` [PATCH 7/7] watchdog: imx93: add watchdog timer on imx93 Alice Guo (OSS)
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