[PATCH v1 1/7] hwmon: (it87) Allow disabling exiting of configuration mode

[Frank Crawford <frank@crawford.emu.id.au>]

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>
---
 drivers/hwmon/it87.c | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/hwmon/it87.c b/drivers/hwmon/it87.c
index a8a6a0ffee82..7049e81f5af1 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 doexit)
 {
-	outb(0x02, ioreg);
-	outb(0x02, ioreg + 1);
+	if (doexit) {
+		outb(0x02, ioreg);
+		outb(0x02, ioreg + 1);
+	}
 	release_region(ioreg, 2);
 }
 
@@ -497,6 +499,7 @@ static const struct it87_devices it87_devices[] = {
 struct it87_sio_data {
 	int sioaddr;
 	enum chips type;
+	u8 doexit;
 	/* Values read from Super-I/O config space */
 	u8 revision;
 	u8 vid_value;
@@ -523,6 +526,8 @@ struct it87_data {
 	u8 peci_mask;
 	u8 old_peci_mask;
 
+	bool doexit;		/* true if exit from sio config is ok */
+
 	unsigned short addr;
 	const char *name;
 	struct mutex update_lock;
@@ -2405,6 +2410,7 @@ static int __init it87_find(int sioaddr, unsigned short *address,
 	int err;
 	u16 chip_type;
 	const struct it87_devices *config;
+	bool doexit = true;
 
 	err = superio_enter(sioaddr);
 	if (err)
@@ -2501,6 +2507,8 @@ static int __init it87_find(int sioaddr, unsigned short *address,
 		goto exit;
 	}
 
+	sio_data->doexit = doexit;
+
 	err = 0;
 	sio_data->sioaddr = sioaddr;
 	sio_data->revision = superio_inb(sioaddr, DEVREV) & 0x0f;
@@ -2827,7 +2835,7 @@ 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, doexit);
 	return err;
 }
 
@@ -3061,6 +3069,7 @@ static int it87_probe(struct platform_device *pdev)
 	data->addr = res->start;
 	data->sioaddr = sio_data->sioaddr;
 	data->type = sio_data->type;
+	data->doexit = sio_data->doexit;
 	data->features = it87_devices[sio_data->type].features;
 	data->peci_mask = it87_devices[sio_data->type].peci_mask;
 	data->old_peci_mask = it87_devices[sio_data->type].old_peci_mask;
@@ -3213,7 +3222,7 @@ static void it87_resume_sio(struct platform_device *pdev)
 			     reg2c);
 	}
 
-	superio_exit(data->sioaddr);
+	superio_exit(data->sioaddr, data->doexit);
 }
 
 static int it87_resume(struct device *dev)
-- 
2.39.1