Commit a160d128 authored by Biju Das's avatar Biju Das Committed by Lee Jones
Browse files

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: default avatarPavel Machek <pavel@denx.de>
Closes: https://lore.kernel.org/all/ZIMAse1ikTuycJ02@duo.ucw.cz/


Signed-off-by: default avatarBiju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: default avatarPavel Machek <pavel@denx.de>
Link: https://lore.kernel.org/r/20230815073445.9579-2-biju.das.jz@bp.renesas.com


Signed-off-by: default avatarLee Jones <lee@kernel.org>
parent 367124eb

drivers/mfd/rz-mtu3.c

+7 −9
Original line number Diff line number Diff line
@@ -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);