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From: Guenter Roeck <linux@roeck-us.net>
To: Frank Crawford <frank@crawford.emu.id.au>
Cc: Jean Delvare <jdelvare@suse.com>, linux-hwmon@vger.kernel.org
Subject: Re: [PATCH v3 1/7] hwmon: (it87) Allow disabling exiting of configuration mode
Date: Sun, 29 Jan 2023 12:56:47 -0800	[thread overview]
Message-ID: <20230129205647.GA1951466@roeck-us.net> (raw)
In-Reply-To: <20230128060308.1549707-2-frank@crawford.emu.id.au>

On Sat, Jan 28, 2023 at 05:03:02PM +1100, Frank Crawford wrote:
> Disabling configuration mode on some chips can result in system
> hang-ups and access failures to the Super-IO chip at the
> second SIO address. Never exit configuration mode on these
> chips to avoid the problem.
> 
> This patch should be applied in conjunction with a previous one to
> initialise the second chip for certain mother boards.
> 
> Signed-off-by: Frank Crawford <frank@crawford.emu.id.au>
> ---
> 
> v3:
>  * Correct possible uninitialised pointer issue.
> 
> v2:
>  * Convert to use feature flag and related macros rather than a separate
>    field, as suggested in review.
>  * Reverse sense of flag in superio_exit to simplify feature macro.
> 
> ---
>  drivers/hwmon/it87.c | 26 ++++++++++++++++++--------
>  1 file changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
> index a8a6a0ffee82..923a9563be92 100644
> --- a/drivers/hwmon/it87.c
> +++ b/drivers/hwmon/it87.c
> @@ -128,10 +128,12 @@ static inline int superio_enter(int ioreg)
>  	return 0;
>  }
>  
> -static inline void superio_exit(int ioreg)
> +static inline void superio_exit(int ioreg, bool noexit)
>  {
> -	outb(0x02, ioreg);
> -	outb(0x02, ioreg + 1);
> +	if (!noexit) {
> +		outb(0x02, ioreg);
> +		outb(0x02, ioreg + 1);
> +	}
>  	release_region(ioreg, 2);
>  }
>  
> @@ -300,6 +302,13 @@ struct it87_devices {
>  #define FEAT_PWM_FREQ2		BIT(16)	/* Separate pwm freq 2 */
>  #define FEAT_SIX_TEMP		BIT(17)	/* Up to 6 temp sensors */
>  #define FEAT_VIN3_5V		BIT(18)	/* VIN3 connected to +5V */
> +/*
> + * Disabling configuration mode on some chips can result in system
> + * hang-ups and access failures to the Super-IO chip at the
> + * second SIO address. Never exit configuration mode on these
> + * chips to avoid the problem.
> + */
> +#define FEAT_CONF_NOEXIT	BIT(28)	/* Chip should not exit conf mode */

Feature bits are supposed to be numbered sequentially, not randomly
assigned. Please use bit 19.

>  
>  static const struct it87_devices it87_devices[] = {
>  	[it87] = {
> @@ -493,6 +502,7 @@ static const struct it87_devices it87_devices[] = {
>  #define has_pwm_freq2(data)	((data)->features & FEAT_PWM_FREQ2)
>  #define has_six_temp(data)	((data)->features & FEAT_SIX_TEMP)
>  #define has_vin3_5v(data)	((data)->features & FEAT_VIN3_5V)
> +#define has_conf_noexit(data)	((data)->features & FEAT_CONF_NOEXIT)
>  
>  struct it87_sio_data {
>  	int sioaddr;
> @@ -2404,7 +2414,7 @@ static int __init it87_find(int sioaddr, unsigned short *address,
>  {
>  	int err;
>  	u16 chip_type;
> -	const struct it87_devices *config;
> +	const struct it87_devices *config = NULL;
>  
>  	err = superio_enter(sioaddr);
>  	if (err)
> @@ -2489,6 +2499,8 @@ static int __init it87_find(int sioaddr, unsigned short *address,
>  		goto exit;
>  	}
>  
> +	config = &it87_devices[sio_data->type];
> +
>  	superio_select(sioaddr, PME);
>  	if (!(superio_inb(sioaddr, IT87_ACT_REG) & 0x01)) {
>  		pr_info("Device not activated, skipping\n");
> @@ -2508,8 +2520,6 @@ static int __init it87_find(int sioaddr, unsigned short *address,
>  		it87_devices[sio_data->type].suffix,
>  		*address, sio_data->revision);
>  
> -	config = &it87_devices[sio_data->type];
> -
>  	/* in7 (VSB or VCCH5V) is always internal on some chips */
>  	if (has_in7_internal(config))
>  		sio_data->internal |= BIT(1);
> @@ -2827,7 +2837,7 @@ static int __init it87_find(int sioaddr, unsigned short *address,
>  		sio_data->skip_pwm |= dmi_data->skip_pwm;
>  
>  exit:
> -	superio_exit(sioaddr);
> +	superio_exit(sioaddr, config ? has_conf_noexit(config) : false);

Nit: "config && has_conf_noexit(config)" would avoid the conditional code.

>  	return err;
>  }
>  
> @@ -3213,7 +3223,7 @@ static void it87_resume_sio(struct platform_device *pdev)
>  			     reg2c);
>  	}
>  
> -	superio_exit(data->sioaddr);
> +	superio_exit(data->sioaddr, has_conf_noexit(data));
>  }
>  
>  static int it87_resume(struct device *dev)

  reply	other threads:[~2023-01-29 20:56 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-28  6:03 [PATCH v3 0/7] hwmon: (it87) Complete handling multi-chip configuration Frank Crawford
2023-01-28  6:03 ` [PATCH v3 1/7] hwmon: (it87) Allow disabling exiting of configuration mode Frank Crawford
2023-01-29 20:56   ` Guenter Roeck [this message]
2023-01-30 18:42     ` Guenter Roeck
2023-01-30 22:19       ` Frank Crawford
2023-01-31  3:40         ` Guenter Roeck
2023-01-28  6:03 ` [PATCH v3 2/7] hwmon: (it87) Disable configuration exit for certain chips Frank Crawford
2023-01-28  6:03 ` [PATCH v3 3/7] hwmon: (it87) List full chip model name Frank Crawford
2023-01-28  6:03 ` [PATCH v3 4/7] hwmon: (it87) Add chip_id in some info message Frank Crawford
2023-01-28  6:03 ` [PATCH v3 5/7] hwmon: (it87) Allow multiple chip IDs for force_id Frank Crawford
2023-01-28  6:03 ` [PATCH v3 6/7] hwmon: (it87) Add new chipset IT87952E Frank Crawford
2023-01-28  6:03 ` [PATCH v3 7/7] hwmon: (it87) Updated documentation for recent updates to it87 Frank Crawford

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