From 2541f7f4c14e2198ed8d8c61c854b86cae238cf1 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 19 Jan 2015 17:22:55 +0100 Subject: i2c: slave-eeprom: fix boundary check when using sysfs Due to a copy&paste error, the last byte of the shared memory was not accessible via sysfs. Reported-by: Debora Grosse Signed-off-by: Wolfram Sang Acked-by: Laurent Pinchart Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-slave-eeprom.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/i2c/i2c-slave-eeprom.c b/drivers/i2c/i2c-slave-eeprom.c index 6631400b5f02..cf9b09db092f 100644 --- a/drivers/i2c/i2c-slave-eeprom.c +++ b/drivers/i2c/i2c-slave-eeprom.c @@ -74,7 +74,7 @@ static ssize_t i2c_slave_eeprom_bin_read(struct file *filp, struct kobject *kobj struct eeprom_data *eeprom; unsigned long flags; - if (off + count >= attr->size) + if (off + count > attr->size) return -EFBIG; eeprom = dev_get_drvdata(container_of(kobj, struct device, kobj)); @@ -92,7 +92,7 @@ static ssize_t i2c_slave_eeprom_bin_write(struct file *filp, struct kobject *kob struct eeprom_data *eeprom; unsigned long flags; - if (off + count >= attr->size) + if (off + count > attr->size) return -EFBIG; eeprom = dev_get_drvdata(container_of(kobj, struct device, kobj)); -- cgit v1.2.3 From 34e81ad5f0b60007c95995eb7803da7e00c6c611 Mon Sep 17 00:00:00 2001 From: Paul Osmialowski Date: Mon, 19 Jan 2015 17:03:33 +0100 Subject: i2c: s3c2410: fix ABBA deadlock by keeping clock prepared This patch solves deadlock between clock prepare mutex and regmap mutex reported by Tomasz Figa in [1] by implementing solution from [2]: "always leave the clock of the i2c controller in a prepared state". [1] https://lkml.org/lkml/2014/7/2/171 [2] https://lkml.org/lkml/2014/7/2/207 On each i2c transfer handled by s3c24xx_i2c_xfer(), clk_prepare_enable() was called, which calls clk_prepare() then clk_enable(). clk_prepare() takes prepare_lock mutex before proceeding. Note that i2c transfer functions are invoked from many places in kernel, typically with some other additional lock held. It may happen that function on CPU1 (e.g. regmap_update_bits()) has taken a mutex (i.e. regmap lock mutex) then it attempts i2c communication in order to proceed (so it needs to obtain clock related prepare_lock mutex during transfer preparation stage due to clk_prepare() call). At the same time other task on CPU0 wants to operate on clock (e.g. to (un)prepare clock for some other reason) so it has taken prepare_lock mutex. CPU0: CPU1: clk_disable_unused() regulator_disable() clk_prepare_lock() map->lock(map->lock_arg) regmap_read() s3c24xx_i2c_xfer() map->lock(map->lock_arg) clk_prepare_lock() Implemented solution from [2] leaves i2c clock prepared. Preparation is done in s3c24xx_i2c_probe() function. Without this patch, it is immediately unprepared by clk_disable_unprepare() call. I've replaced this call with clk_disable() and I've added clk_unprepare() call in s3c24xx_i2c_remove(). The s3c24xx_i2c_xfer() function now uses clk_enable() instead of clk_prepare_enable() (and clk_disable() instead of clk_unprepare_disable()). Signed-off-by: Paul Osmialowski Reviewed-by: Krzysztof Kozlowski Signed-off-by: Wolfram Sang Cc: stable@kernel.org --- drivers/i2c/busses/i2c-s3c2410.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c index bff20a589621..958c8db4ec30 100644 --- a/drivers/i2c/busses/i2c-s3c2410.c +++ b/drivers/i2c/busses/i2c-s3c2410.c @@ -785,14 +785,16 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap, int ret; pm_runtime_get_sync(&adap->dev); - clk_prepare_enable(i2c->clk); + ret = clk_enable(i2c->clk); + if (ret) + return ret; for (retry = 0; retry < adap->retries; retry++) { ret = s3c24xx_i2c_doxfer(i2c, msgs, num); if (ret != -EAGAIN) { - clk_disable_unprepare(i2c->clk); + clk_disable(i2c->clk); pm_runtime_put(&adap->dev); return ret; } @@ -802,7 +804,7 @@ static int s3c24xx_i2c_xfer(struct i2c_adapter *adap, udelay(100); } - clk_disable_unprepare(i2c->clk); + clk_disable(i2c->clk); pm_runtime_put(&adap->dev); return -EREMOTEIO; } @@ -1197,7 +1199,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) clk_prepare_enable(i2c->clk); ret = s3c24xx_i2c_init(i2c); - clk_disable_unprepare(i2c->clk); + clk_disable(i2c->clk); if (ret != 0) { dev_err(&pdev->dev, "I2C controller init failed\n"); return ret; @@ -1210,6 +1212,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) i2c->irq = ret = platform_get_irq(pdev, 0); if (ret <= 0) { dev_err(&pdev->dev, "cannot find IRQ\n"); + clk_unprepare(i2c->clk); return ret; } @@ -1218,6 +1221,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) if (ret != 0) { dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq); + clk_unprepare(i2c->clk); return ret; } } @@ -1225,6 +1229,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) ret = s3c24xx_i2c_register_cpufreq(i2c); if (ret < 0) { dev_err(&pdev->dev, "failed to register cpufreq notifier\n"); + clk_unprepare(i2c->clk); return ret; } @@ -1241,6 +1246,7 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev) if (ret < 0) { dev_err(&pdev->dev, "failed to add bus to i2c core\n"); s3c24xx_i2c_deregister_cpufreq(i2c); + clk_unprepare(i2c->clk); return ret; } @@ -1262,6 +1268,8 @@ static int s3c24xx_i2c_remove(struct platform_device *pdev) { struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev); + clk_unprepare(i2c->clk); + pm_runtime_disable(&i2c->adap.dev); pm_runtime_disable(&pdev->dev); @@ -1293,13 +1301,16 @@ static int s3c24xx_i2c_resume_noirq(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev); + int ret; if (!IS_ERR(i2c->sysreg)) regmap_write(i2c->sysreg, EXYNOS5_SYS_I2C_CFG, i2c->sys_i2c_cfg); - clk_prepare_enable(i2c->clk); + ret = clk_enable(i2c->clk); + if (ret) + return ret; s3c24xx_i2c_init(i2c); - clk_disable_unprepare(i2c->clk); + clk_disable(i2c->clk); i2c->suspended = 0; return 0; -- cgit v1.2.3 From d5fd120e7860c2b3d4c936a2ebadb6b244bec4c8 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Mon, 26 Jan 2015 20:59:31 +0100 Subject: i2c: Only include slave support if selected Make the slave support depend on CONFIG_I2C_SLAVE. Otherwise it gets included unconditionally, even when it is not needed. I2C bus drivers which implement slave support must select I2C_SLAVE. Signed-off-by: Jean Delvare Signed-off-by: Wolfram Sang --- drivers/i2c/busses/Kconfig | 1 + drivers/i2c/i2c-core.c | 2 ++ include/linux/i2c.h | 6 ++++++ 3 files changed, 9 insertions(+) (limited to 'drivers') diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 31e8308ba899..ab838d9e28b6 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -881,6 +881,7 @@ config I2C_XLR config I2C_RCAR tristate "Renesas R-Car I2C Controller" depends on ARCH_SHMOBILE || COMPILE_TEST + select I2C_SLAVE help If you say yes to this option, support will be included for the R-Car I2C controller. diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 39d25a8cb1ad..e9eae57a2b50 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -2972,6 +2972,7 @@ trace: } EXPORT_SYMBOL(i2c_smbus_xfer); +#if IS_ENABLED(CONFIG_I2C_SLAVE) int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb) { int ret; @@ -3019,6 +3020,7 @@ int i2c_slave_unregister(struct i2c_client *client) return ret; } EXPORT_SYMBOL_GPL(i2c_slave_unregister); +#endif MODULE_AUTHOR("Simon G. Vogl "); MODULE_DESCRIPTION("I2C-Bus main module"); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index e3a1721c8354..7c7695940ddd 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -228,7 +228,9 @@ struct i2c_client { struct device dev; /* the device structure */ int irq; /* irq issued by device */ struct list_head detected; +#if IS_ENABLED(CONFIG_I2C_SLAVE) i2c_slave_cb_t slave_cb; /* callback for slave mode */ +#endif }; #define to_i2c_client(d) container_of(d, struct i2c_client, dev) @@ -253,6 +255,7 @@ static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) /* I2C slave support */ +#if IS_ENABLED(CONFIG_I2C_SLAVE) enum i2c_slave_event { I2C_SLAVE_REQ_READ_START, I2C_SLAVE_REQ_READ_END, @@ -269,6 +272,7 @@ static inline int i2c_slave_event(struct i2c_client *client, { return client->slave_cb(client, event, val); } +#endif /** * struct i2c_board_info - template for device creation @@ -404,8 +408,10 @@ struct i2c_algorithm { /* To determine what the adapter supports */ u32 (*functionality) (struct i2c_adapter *); +#if IS_ENABLED(CONFIG_I2C_SLAVE) int (*reg_slave)(struct i2c_client *client); int (*unreg_slave)(struct i2c_client *client); +#endif }; /** -- cgit v1.2.3 From 32e224090fa310a58fdb47049caf631272ceb044 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Thu, 29 Jan 2015 18:33:16 +0100 Subject: i2c: sh_mobile: terminate DMA reads properly DMA read requests could miss proper termination, so two more bytes would have been read via PIO overwriting the end of the buffer with wrong data. Make DMA stop handling more readable while we are here. Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-sh_mobile.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index 440d5dbc8b5f..007818b3e174 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -139,6 +139,7 @@ struct sh_mobile_i2c_data { int pos; int sr; bool send_stop; + bool stop_after_dma; struct resource *res; struct dma_chan *dma_tx; @@ -407,7 +408,7 @@ static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd) if (pd->pos == pd->msg->len) { /* Send stop if we haven't yet (DMA case) */ - if (pd->send_stop && (iic_rd(pd, ICCR) & ICCR_BBSY)) + if (pd->send_stop && pd->stop_after_dma) i2c_op(pd, OP_TX_STOP, 0); return 1; } @@ -449,6 +450,13 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd) real_pos = pd->pos - 2; if (pd->pos == pd->msg->len) { + if (pd->stop_after_dma) { + /* Simulate PIO end condition after DMA transfer */ + i2c_op(pd, OP_RX_STOP, 0); + pd->pos++; + break; + } + if (real_pos < 0) { i2c_op(pd, OP_RX_STOP, 0); break; @@ -536,6 +544,7 @@ static void sh_mobile_i2c_dma_callback(void *data) sh_mobile_i2c_dma_unmap(pd); pd->pos = pd->msg->len; + pd->stop_after_dma = true; iic_set_clr(pd, ICIC, 0, ICIC_TDMAE | ICIC_RDMAE); } @@ -726,6 +735,7 @@ static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter, bool do_start = pd->send_stop || !i; msg = &msgs[i]; pd->send_stop = i == num - 1 || msg->flags & I2C_M_STOP; + pd->stop_after_dma = false; err = start_ch(pd, msg, do_start); if (err) -- cgit v1.2.3