hwmon: (vt1211) Use request_muxed_region for Super-IO accesses (14b97ba5) · Commits · 戴 / test

Super-IO accesses may fail on a system with no or unmapped LPC bus. Also, other drivers may attempt to access the LPC bus at the same time, resulting in undefined behavior. Use request_muxed_region() to ensure that IO access on the requested address space is supported, and to ensure that access by multiple drivers is synchronized. Fixes: ("hwmon/vt1211: Add probing of alternate config index port") Signed-off-by:

Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/vt1211.c

+12 −3

Original line number	Diff line number	Diff line
		@@ -226,15 +226,21 @@ static inline void superio_select(int sio_cip, int ldn)
		outb(ldn, sio_cip + 1);
		}

		static inline void superio_enter(int sio_cip)
		static inline int superio_enter(int sio_cip)
		{
		if (!request_muxed_region(sio_cip, 2, DRVNAME))
		return -EBUSY;

		outb(0x87, sio_cip);
		outb(0x87, sio_cip);

		return 0;
		}

		static inline void superio_exit(int sio_cip)
		{
		outb(0xaa, sio_cip);
		release_region(sio_cip, 2);
		}

		/* ---------------------------------------------------------------------
		@@ -1282,11 +1288,14 @@ EXIT:

		static int __init vt1211_find(int sio_cip, unsigned short *address)
		{
		int err = -ENODEV;
		int err;
		int devid;

		superio_enter(sio_cip);
		err = superio_enter(sio_cip);
		if (err)
		return err;

		err = -ENODEV;
		devid = force_id ? force_id : superio_inb(sio_cip, SIO_VT1211_DEVID);
		if (devid != SIO_VT1211_ID)
		goto EXIT;

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