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[103.232.208.193]) by smtp.gmail.com with ESMTPSA id h3sm12540589pfc.82.2017.02.23.21.16.03 (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 23 Feb 2017 21:16:05 -0800 (PST) Received: by aurora.jms.id.au (sSMTP sendmail emulation); Fri, 24 Feb 2017 15:45:58 +1030 From: Joel Stanley To: openbmc@lists.ozlabs.org Subject: [PATCH linux dev-4.7] i2c: aspeed: drop the locks Date: Fri, 24 Feb 2017 15:45:56 +1030 Message-Id: <20170224051556.16432-1-joel@jms.id.au> X-Mailer: git-send-email 2.11.0 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: andrew@aj.id.au Errors-To: openbmc-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "openbmc" The i2c core code provides i2c_lock_bus. This gives all i2c buses a per-adapter lock, so the locking we perform in the driver is redundant. Tested on Zaius by using the UDC and EEPROM which are on the same i2c bus. Suggested-by: Andrew Jeffery Signed-off-by: Joel Stanley --- drivers/i2c/busses/i2c-aspeed.c | 27 ++------------------------- 1 file changed, 2 insertions(+), 25 deletions(-) diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index ece5aa3ecfd1..61da89407895 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -252,9 +252,6 @@ struct ast_i2c_bus { struct clk *pclk; int irq; - /* i2c transfer state. this is accessed from both process and IRQ - * context, so is protected by cmd_lock */ - spinlock_t cmd_lock; bool send_start; bool send_stop; /* last message of an xfer? */ bool query_len; @@ -358,10 +355,8 @@ static void ast_i2c_issue_cmd(struct ast_i2c_bus *bus, u32 cmd) static int ast_i2c_issue_oob_command(struct ast_i2c_bus *bus, u32 cmd) { - spin_lock_irq(&bus->cmd_lock); init_completion(&bus->cmd_complete); ast_i2c_issue_cmd(bus, cmd); - spin_unlock_irq(&bus->cmd_lock); return wait_for_completion_interruptible_timeout(&bus->cmd_complete, bus->adap.timeout*HZ); } @@ -539,8 +534,9 @@ static void ast_i2c_master_xfer_done(struct ast_i2c_bus *bus) /* queue the next message. If there's none left, we notify the * waiter */ next_msg_queued = ast_i2c_do_byte_xfer(bus); - if (!next_msg_queued) + if (!next_msg_queued) { complete(&bus->cmd_complete); + } } #if IS_ENABLED(CONFIG_I2C_SLAVE) @@ -554,7 +550,6 @@ static bool ast_i2c_slave_irq(struct ast_i2c_bus *bus) enum i2c_slave_event event; struct i2c_client *slave = bus->slave; - spin_lock(&bus->cmd_lock); if (!slave) { irq_handled = false; goto out; @@ -635,7 +630,6 @@ static bool ast_i2c_slave_irq(struct ast_i2c_bus *bus) ast_i2c_write(bus, status_ack, I2C_INTR_STS_REG); out: - spin_unlock(&bus->cmd_lock); return irq_handled; } #endif @@ -649,7 +643,6 @@ static bool ast_i2c_master_irq(struct ast_i2c_bus *bus) AST_I2CD_INTR_TX_NAK; u32 sts, cmd; - spin_lock(&bus->cmd_lock); cmd = ast_i2c_read(bus, I2C_CMD_REG); sts = ast_i2c_read(bus, I2C_INTR_STS_REG); @@ -708,8 +701,6 @@ static bool ast_i2c_master_irq(struct ast_i2c_bus *bus) bus->msg, bus->cmd_pending); } - spin_unlock(&bus->cmd_lock); - return true; } @@ -734,13 +725,11 @@ static irqreturn_t ast_i2c_bus_irq(int irq, void *dev_id) static int ast_i2c_do_msgs_xfer(struct ast_i2c_bus *bus, struct i2c_msg *msgs, int num) { - unsigned long flags; int i, ret = 0; u32 err, cmd; for (i = 0; i < num; i++) { - spin_lock_irqsave(&bus->cmd_lock, flags); bus->msg = &msgs[i]; bus->msg_pos = 0; bus->query_len = bus->msg->flags & I2C_M_RECV_LEN; @@ -749,18 +738,15 @@ static int ast_i2c_do_msgs_xfer(struct ast_i2c_bus *bus, init_completion(&bus->cmd_complete); ast_i2c_do_byte_xfer(bus); - spin_unlock_irqrestore(&bus->cmd_lock, flags); ret = wait_for_completion_interruptible_timeout( &bus->cmd_complete, bus->adap.timeout * HZ); - spin_lock_irqsave(&bus->cmd_lock, flags); err = bus->cmd_err; cmd = bus->cmd_sent; bus->cmd_sent = 0; bus->msg = NULL; - spin_unlock_irqrestore(&bus->cmd_lock, flags); if (!ret) { dev_dbg(bus->dev, "controller timed out\n"); @@ -831,14 +817,11 @@ static u32 ast_i2c_functionality(struct i2c_adapter *adap) static int ast_i2c_reg_slave(struct i2c_client *client) { struct ast_i2c_bus *bus; - unsigned long flags; u32 addr_reg_val; u32 func_ctrl_reg_val; bus = client->adapter->algo_data; - spin_lock_irqsave(&bus->cmd_lock, flags); if (bus->slave) { - spin_unlock_irqrestore(&bus->cmd_lock, flags); return -EINVAL; } @@ -856,20 +839,16 @@ static int ast_i2c_reg_slave(struct i2c_client *client) bus->slave = client; bus->slave_state = AST_I2C_SLAVE_STOP; - spin_unlock_irqrestore(&bus->cmd_lock, flags); return 0; } static int ast_i2c_unreg_slave(struct i2c_client *client) { struct ast_i2c_bus *bus = client->adapter->algo_data; - unsigned long flags; u32 addr_reg_val; u32 func_ctrl_reg_val; - spin_lock_irqsave(&bus->cmd_lock, flags); if (!bus->slave) { - spin_unlock_irqrestore(&bus->cmd_lock, flags); return -EINVAL; } @@ -880,7 +859,6 @@ static int ast_i2c_unreg_slave(struct i2c_client *client) ast_i2c_write(bus, func_ctrl_reg_val, I2C_FUN_CTRL_REG); bus->slave = NULL; - spin_unlock_irqrestore(&bus->cmd_lock, flags); return 0; } #endif @@ -933,7 +911,6 @@ static int ast_i2c_probe_bus(struct platform_device *pdev) } /* Initialize the I2C adapter */ - spin_lock_init(&bus->cmd_lock); bus->adap.nr = bus_num; bus->adap.owner = THIS_MODULE; bus->adap.retries = 0;