mfd: rz-mtu3: Reduce critical sections

Reduce critical sections on rz_mtu3_start_stop_ch() and
rz_mtu3_is_enabled() by moving offset and bitpos computation
outside the critical section and drop the 'ret' variable on
rz_mtu3_is_enabled() and return 'tstr & BIT(bitpos)' directly.

Reported-by: Pavel Machek <pavel@denx.de>
Closes: https://lore.kernel.org/all/ZIMAse1ikTuycJ02@duo.ucw.cz/
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Pavel Machek <pavel@denx.de>
Link: https://lore.kernel.org/r/20230815073445.9579-2-biju.das.jz@bp.renesas.com
Signed-off-by: Lee Jones <lee@kernel.org>

diff --git a/drivers/mfd/rz-mtu3.c b/drivers/mfd/rz-mtu3.c
index d25109d..44133fc 100644 (file)
--- a/drivers/mfd/rz-mtu3.c
+++ b/drivers/mfd/rz-mtu3.c
@@ -252,11 +252,12 @@ static void rz_mtu3_start_stop_ch(struct rz_mtu3_channel *ch, bool start)
        u16 offset;
        u8 bitpos;
 
+       offset = rz_mtu3_get_tstr_offset(ch);
+       bitpos = rz_mtu3_get_tstr_bit_pos(ch);
+
        /* start stop register shared by multiple timer channels */
        raw_spin_lock_irqsave(&priv->lock, flags);
 
-       offset = rz_mtu3_get_tstr_offset(ch);
-       bitpos = rz_mtu3_get_tstr_bit_pos(ch);
        tstr = rz_mtu3_shared_reg_read(ch, offset);
        __assign_bit(bitpos, &tstr, start);
        rz_mtu3_shared_reg_write(ch, offset, tstr);
@@ -269,21 +270,18 @@ bool rz_mtu3_is_enabled(struct rz_mtu3_channel *ch)
        struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
        struct rz_mtu3_priv *priv = mtu->priv_data;
        unsigned long flags, tstr;
-       bool ret = false;
        u16 offset;
        u8 bitpos;
 
-       /* start stop register shared by multiple timer channels */
-       raw_spin_lock_irqsave(&priv->lock, flags);
-
        offset = rz_mtu3_get_tstr_offset(ch);
        bitpos = rz_mtu3_get_tstr_bit_pos(ch);
-       tstr = rz_mtu3_shared_reg_read(ch, offset);
-       ret = tstr & BIT(bitpos);
 
+       /* start stop register shared by multiple timer channels */
+       raw_spin_lock_irqsave(&priv->lock, flags);
+       tstr = rz_mtu3_shared_reg_read(ch, offset);
        raw_spin_unlock_irqrestore(&priv->lock, flags);
 
-       return ret;
+       return tstr & BIT(bitpos);
 }
 EXPORT_SYMBOL_GPL(rz_mtu3_is_enabled);