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: Rakesh Iyer <riyer@nvidia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/keyboard/tegra-kbc.c b/drivers/input/keyboard/tegra-kbc.c
index 8fb474f..cf3228b 100644
--- a/drivers/input/keyboard/tegra-kbc.c
+++ b/drivers/input/keyboard/tegra-kbc.c
@@ -260,12 +260,10 @@
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 @@
* 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 @@
}
}
- 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 @@
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 @@
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 @@
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 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 @@
* 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 @@
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);