From: Joel Stanley <joel@jms.id.au>
To: John Wang <wangzhiqiang.bj@bytedance.com>,
SoC Team <soc@kernel.org>, Arnd Bergmann <arnd@arndb.de>
Cc: xuxiaohan@bytedance.com, 郁雷 <yulei.sh@bytedance.com>,
"Jae Hyun Yoo" <jae.hyun.yoo@intel.com>,
"Vernon Mauery" <vernon.mauery@linux.intel.com>,
"Andrew Jeffery" <andrew@aj.id.au>,
"Patrick Venture" <venture@google.com>,
"Robert Lippert" <rlippert@google.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Benjamin Fair" <benjaminfair@google.com>,
"moderated list:ARM/ASPEED MACHINE SUPPORT"
<linux-arm-kernel@lists.infradead.org>,
"moderated list:ARM/ASPEED MACHINE SUPPORT"
<linux-aspeed@lists.ozlabs.org>,
"open list" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 1/2] misc: Add clock control logic into Aspeed LPC SNOOP driver
Date: Wed, 9 Dec 2020 02:17:40 +0000 [thread overview]
Message-ID: <CACPK8XePhJj8HzbLB4QgJQCjTuH_kPq=sWyOhdcGPmptqD6Aqw@mail.gmail.com> (raw)
In-Reply-To: <20201208091748.1920-1-wangzhiqiang.bj@bytedance.com>
On Tue, 8 Dec 2020 at 09:17, John Wang <wangzhiqiang.bj@bytedance.com> wrote:
>
> From: Jae Hyun Yoo <jae.hyun.yoo@intel.com>
>
> If LPC SNOOP driver is registered ahead of lpc-ctrl module, LPC
> SNOOP block will be enabled without heart beating of LCLK until
> lpc-ctrl enables the LCLK. This issue causes improper handling on
> host interrupts when the host sends interrupt in that time frame.
> Then kernel eventually forcibly disables the interrupt with
> dumping stack and printing a 'nobody cared this irq' message out.
>
> To prevent this issue, all LPC sub-nodes should enable LCLK
> individually so this patch adds clock control logic into the LPC
> SNOOP driver.
>
> Fixes: 3772e5da4454 ("drivers/misc: Aspeed LPC snoop output using misc
> chardev")
>
> Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@intel.com>
> Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
> Signed-off-by: John Wang <wangzhiqiang.bj@bytedance.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Arnd, can you merge this for v5.11, or would you prefer me to do a pull request?
The device tree patch from this series also needs to be added.
Cheers,
Joel
> ---
> v2:
> reword: Add fixes line
> ---
> drivers/soc/aspeed/aspeed-lpc-snoop.c | 30 ++++++++++++++++++++++++---
> 1 file changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/soc/aspeed/aspeed-lpc-snoop.c b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> index 682ba0eb4eba..20acac6342ef 100644
> --- a/drivers/soc/aspeed/aspeed-lpc-snoop.c
> +++ b/drivers/soc/aspeed/aspeed-lpc-snoop.c
> @@ -11,6 +11,7 @@
> */
>
> #include <linux/bitops.h>
> +#include <linux/clk.h>
> #include <linux/interrupt.h>
> #include <linux/fs.h>
> #include <linux/kfifo.h>
> @@ -67,6 +68,7 @@ struct aspeed_lpc_snoop_channel {
> struct aspeed_lpc_snoop {
> struct regmap *regmap;
> int irq;
> + struct clk *clk;
> struct aspeed_lpc_snoop_channel chan[NUM_SNOOP_CHANNELS];
> };
>
> @@ -282,22 +284,42 @@ static int aspeed_lpc_snoop_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> + lpc_snoop->clk = devm_clk_get(dev, NULL);
> + if (IS_ERR(lpc_snoop->clk)) {
> + rc = PTR_ERR(lpc_snoop->clk);
> + if (rc != -EPROBE_DEFER)
> + dev_err(dev, "couldn't get clock\n");
> + return rc;
> + }
> + rc = clk_prepare_enable(lpc_snoop->clk);
> + if (rc) {
> + dev_err(dev, "couldn't enable clock\n");
> + return rc;
> + }
> +
> rc = aspeed_lpc_snoop_config_irq(lpc_snoop, pdev);
> if (rc)
> - return rc;
> + goto err;
>
> rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 0, port);
> if (rc)
> - return rc;
> + goto err;
>
> /* Configuration of 2nd snoop channel port is optional */
> if (of_property_read_u32_index(dev->of_node, "snoop-ports",
> 1, &port) == 0) {
> rc = aspeed_lpc_enable_snoop(lpc_snoop, dev, 1, port);
> - if (rc)
> + if (rc) {
> aspeed_lpc_disable_snoop(lpc_snoop, 0);
> + goto err;
> + }
> }
>
> + return 0;
> +
> +err:
> + clk_disable_unprepare(lpc_snoop->clk);
> +
> return rc;
> }
>
> @@ -309,6 +331,8 @@ static int aspeed_lpc_snoop_remove(struct platform_device *pdev)
> aspeed_lpc_disable_snoop(lpc_snoop, 0);
> aspeed_lpc_disable_snoop(lpc_snoop, 1);
>
> + clk_disable_unprepare(lpc_snoop->clk);
> +
> return 0;
> }
>
> --
> 2.25.1
>
next prev parent reply other threads:[~2020-12-09 2:18 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-08 9:17 [PATCH v2 1/2] misc: Add clock control logic into Aspeed LPC SNOOP driver John Wang
2020-12-08 9:17 ` [PATCH v2 2/2] ARM: dts: aspeed: Add LCLK to lpc-snoop John Wang
2020-12-09 2:17 ` Joel Stanley [this message]
2021-01-06 9:54 ` [PATCH v2 1/2] misc: Add clock control logic into Aspeed LPC SNOOP driver Ryan Chen
2021-01-15 17:04 ` Arnd Bergmann
2021-01-16 1:03 ` Ryan Chen
2021-02-09 23:27 ` Arnd Bergmann
2021-02-10 10:18 ` Joel Stanley
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