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Commit 95439cba authored by Dmitry Torokhov's avatar Dmitry Torokhov
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Input: tegra-kbc - tighten locking 



Take spinlock when entering ISR and timer routine to ensure that we do not
race while enabling/disabling FIFO interrupts.

Also we do not need to take teh spinlock in tegra_kbc_startremove() since
interrupt is completely disabled.

Tested-by: default avatarRakesh Iyer <riyer@nvidia.com>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent d0d150ec

drivers/input/keyboard/tegra-kbc.c

+12 −19
Original line number Diff line number Diff line
@@ -260,12 +260,10 @@ static void tegra_kbc_report_keys(struct tegra_kbc *kbc) 
	u32 val = 0;

	unsigned int i;

	unsigned int num_down = 0;

	unsigned long flags;

	bool fn_keypress = false;

	bool key_in_same_row = false;

	bool key_in_same_col = false;



	spin_lock_irqsave(&kbc->lock, flags);

	for (i = 0; i < KBC_MAX_KPENT; i++) {

		if ((i % 4) == 0)

			val = readl(kbc->mmio + KBC_KP_ENT0_0 + i);
@@ -294,7 +292,7 @@ static void tegra_kbc_report_keys(struct tegra_kbc *kbc) 
	 * any 2 of the 3 keys share a row, and any 2 of them share a column.

	 * If so ignore the key presses for this iteration.

	 */

	if ((kbc->use_ghost_filter) && (num_down >= 3)) {

	if (kbc->use_ghost_filter && num_down >= 3) {

		for (i = 0; i < num_down; i++) {

			unsigned int j;

			u8 curr_col = scancodes[i] & 0x07;
@@ -327,8 +325,6 @@ static void tegra_kbc_report_keys(struct tegra_kbc *kbc) 
		}

	}



	spin_unlock_irqrestore(&kbc->lock, flags);



	/* Ignore the key presses for this iteration? */

	if (key_in_same_col && key_in_same_row)

		return;
@@ -362,6 +358,8 @@ static void tegra_kbc_keypress_timer(unsigned long data) 
	u32 val;

	unsigned int i;



	spin_lock_irqsave(&kbc->lock, flags);



	val = (readl(kbc->mmio + KBC_INT_0) >> 4) & 0xf;

	if (val) {

		unsigned long dly;
@@ -383,22 +381,19 @@ static void tegra_kbc_keypress_timer(unsigned long data) 
		kbc->num_pressed_keys = 0;



		/* All keys are released so enable the keypress interrupt */

		spin_lock_irqsave(&kbc->lock, flags);

		tegra_kbc_set_fifo_interrupt(kbc, true);

		spin_unlock_irqrestore(&kbc->lock, flags);

	}



	spin_unlock_irqrestore(&kbc->lock, flags);

}



static irqreturn_t tegra_kbc_isr(int irq, void *args)

{

	struct tegra_kbc *kbc = args;

	unsigned long flags;

	u32 val;



	/*

	 * Until all keys are released, defer further processing to

	 * the polling loop in tegra_kbc_keypress_timer

	 */

	tegra_kbc_set_fifo_interrupt(kbc, false);

	spin_lock_irqsave(&kbc->lock, flags);



	/*

	 * Quickly bail out & reenable interrupts if the fifo threshold
@@ -409,14 +404,15 @@ static irqreturn_t tegra_kbc_isr(int irq, void *args) 


	if (val & KBC_INT_FIFO_CNT_INT_STATUS) {

		/*

		 * Schedule timer to run when hardware is in continuous

		 * polling mode.

		 * Until all keys are released, defer further processing to

		 * the polling loop in tegra_kbc_keypress_timer.

		 */

		tegra_kbc_set_fifo_interrupt(kbc, false);

		mod_timer(&kbc->timer, jiffies + kbc->cp_dly_jiffies);

	} else {

		tegra_kbc_set_fifo_interrupt(kbc, true);

	}



	spin_unlock_irqrestore(&kbc->lock, flags);



	return IRQ_HANDLED;

}
@@ -464,7 +460,6 @@ static void tegra_kbc_config_pins(struct tegra_kbc *kbc) 
static int tegra_kbc_start(struct tegra_kbc *kbc)

{

	const struct tegra_kbc_platform_data *pdata = kbc->pdata;

	unsigned long flags;

	unsigned int debounce_cnt;

	u32 val = 0;
@@ -502,7 +497,6 @@ static int tegra_kbc_start(struct tegra_kbc *kbc) 
	 * Atomically clear out any remaining entries in the key FIFO

	 * and enable keyboard interrupts.

	 */

	spin_lock_irqsave(&kbc->lock, flags);

	while (1) {

		val = readl(kbc->mmio + KBC_INT_0);

		val >>= 4;
@@ -513,7 +507,6 @@ static int tegra_kbc_start(struct tegra_kbc *kbc) 
		val = readl(kbc->mmio + KBC_KP_ENT1_0);

	}

	writel(0x7, kbc->mmio + KBC_INT_0);

	spin_unlock_irqrestore(&kbc->lock, flags);



	enable_irq(kbc->irq);