Commit 84052541 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman
Browse files

Merge tag 'counter-fixes-6.3a' of... 

Merge tag 'counter-fixes-6.3a' of git://git.kernel.org/pub/scm/linux/kernel/git/wbg/counter into char-misc-linus

William writes:

First set of Counter driver fixes for 6.3

This set consists of two fixes for the 104-quad-8 driver:
	- fix a read race condition between the FLAG and CNTR registers
	  (as a result 25-bit count values are no longer supported)
	- invert condition check to report correct Index Synapse action

* tag 'counter-fixes-6.3a' of git://git.kernel.org/pub/scm/linux/kernel/git/wbg/counter:
  counter: 104-quad-8: Fix Synapse action reported for Index signals
  counter: 104-quad-8: Fix race condition between FLAG and CNTR reads
parents e8d018dd 00f4bc51

drivers/counter/104-quad-8.c

+9 −22
Original line number Diff line number Diff line
@@ -97,10 +97,6 @@ struct quad8 { 
	struct quad8_reg __iomem *reg;

};



/* Borrow Toggle flip-flop */

#define QUAD8_FLAG_BT BIT(0)

/* Carry Toggle flip-flop */

#define QUAD8_FLAG_CT BIT(1)

/* Error flag */

#define QUAD8_FLAG_E BIT(4)

/* Up/Down flag */
@@ -133,6 +129,9 @@ struct quad8 { 
#define QUAD8_CMR_QUADRATURE_X2 0x10

#define QUAD8_CMR_QUADRATURE_X4 0x18



/* Each Counter is 24 bits wide */

#define LS7267_CNTR_MAX GENMASK(23, 0)



static int quad8_signal_read(struct counter_device *counter,

			     struct counter_signal *signal,

			     enum counter_signal_level *level)
@@ -156,18 +155,10 @@ static int quad8_count_read(struct counter_device *counter, 
{

	struct quad8 *const priv = counter_priv(counter);

	struct channel_reg __iomem *const chan = priv->reg->channel + count->id;

	unsigned int flags;

	unsigned int borrow;

	unsigned int carry;

	unsigned long irqflags;

	int i;



	flags = ioread8(&chan->control);

	borrow = flags & QUAD8_FLAG_BT;

	carry = !!(flags & QUAD8_FLAG_CT);



	/* Borrow XOR Carry effectively doubles count range */

	*val = (unsigned long)(borrow ^ carry) << 24;

	*val = 0;



	spin_lock_irqsave(&priv->lock, irqflags);
@@ -191,8 +182,7 @@ static int quad8_count_write(struct counter_device *counter, 
	unsigned long irqflags;

	int i;



	/* Only 24-bit values are supported */

	if (val > 0xFFFFFF)

	if (val > LS7267_CNTR_MAX)

		return -ERANGE;



	spin_lock_irqsave(&priv->lock, irqflags);
@@ -378,7 +368,7 @@ static int quad8_action_read(struct counter_device *counter, 


	/* Handle Index signals */

	if (synapse->signal->id >= 16) {

		if (priv->preset_enable[count->id])

		if (!priv->preset_enable[count->id])

			*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;

		else

			*action = COUNTER_SYNAPSE_ACTION_NONE;
@@ -806,8 +796,7 @@ static int quad8_count_preset_write(struct counter_device *counter, 
	struct quad8 *const priv = counter_priv(counter);

	unsigned long irqflags;



	/* Only 24-bit values are supported */

	if (preset > 0xFFFFFF)

	if (preset > LS7267_CNTR_MAX)

		return -ERANGE;



	spin_lock_irqsave(&priv->lock, irqflags);
@@ -834,8 +823,7 @@ static int quad8_count_ceiling_read(struct counter_device *counter, 
		*ceiling = priv->preset[count->id];

		break;

	default:

		/* By default 0x1FFFFFF (25 bits unsigned) is maximum count */

		*ceiling = 0x1FFFFFF;

		*ceiling = LS7267_CNTR_MAX;

		break;

	}
@@ -850,8 +838,7 @@ static int quad8_count_ceiling_write(struct counter_device *counter, 
	struct quad8 *const priv = counter_priv(counter);

	unsigned long irqflags;



	/* Only 24-bit values are supported */

	if (ceiling > 0xFFFFFF)

	if (ceiling > LS7267_CNTR_MAX)

		return -ERANGE;



	spin_lock_irqsave(&priv->lock, irqflags);