From 95439cbad134de58d9ea256e37fd13fbcdc87d08 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Fri, 9 Sep 2011 09:24:20 -0700 Subject: [PATCH] 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 Signed-off-by: Dmitry Torokhov --- drivers/input/keyboard/tegra-kbc.c | 31 ++++++++++++------------------- 1 file changed, 12 insertions(+), 19 deletions(-) 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 @@ 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); -- 2.7.4