From e6f34cea56f5b95498070eaa9f4aa3ba4a9e4f62 Mon Sep 17 00:00:00 2001 From: Josef Ahmad Date: Fri, 19 Apr 2013 17:28:10 +0100 Subject: i2c: designware: fix RX FIFO overrun i2c_dw_xfer_msg() pushes a number of bytes to transmit/receive to/from the bus into the TX FIFO. For master-rx transactions, the maximum amount of data that can be received is calculated depending solely on TX and RX FIFO load. This is racy - TX FIFO may contain master-rx data yet to be processed, which will eventually land into the RX FIFO. This data is not taken into account and the function may request more data than the controller is actually capable of storing. This patch ensures the driver takes into account the outstanding master-rx data in TX FIFO to prevent RX FIFO overrun. Signed-off-by: Josef Ahmad Acked-by: Mika Westerberg Signed-off-by: Wolfram Sang Cc: stable@kernel.org --- drivers/i2c/busses/i2c-designware-core.c | 11 ++++++++++- drivers/i2c/busses/i2c-designware-core.h | 2 ++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 21fbb340ad6..1f06c8e9934 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -448,8 +448,14 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) cmd |= BIT(9); if (msgs[dev->msg_write_idx].flags & I2C_M_RD) { + + /* avoid rx buffer overrun */ + if (rx_limit - dev->rx_outstanding <= 0) + break; + dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD); rx_limit--; + dev->rx_outstanding++; } else dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD); tx_limit--; buf_len--; @@ -502,8 +508,10 @@ i2c_dw_read(struct dw_i2c_dev *dev) rx_valid = dw_readl(dev, DW_IC_RXFLR); - for (; len > 0 && rx_valid > 0; len--, rx_valid--) + for (; len > 0 && rx_valid > 0; len--, rx_valid--) { *buf++ = dw_readl(dev, DW_IC_DATA_CMD); + dev->rx_outstanding--; + } if (len > 0) { dev->status |= STATUS_READ_IN_PROGRESS; @@ -561,6 +569,7 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) dev->msg_err = 0; dev->status = STATUS_IDLE; dev->abort_source = 0; + dev->rx_outstanding = 0; ret = i2c_dw_wait_bus_not_busy(dev); if (ret < 0) diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 9c1840ee09c..e761ad18dd6 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -60,6 +60,7 @@ * @adapter: i2c subsystem adapter node * @tx_fifo_depth: depth of the hardware tx fifo * @rx_fifo_depth: depth of the hardware rx fifo + * @rx_outstanding: current master-rx elements in tx fifo */ struct dw_i2c_dev { struct device *dev; @@ -88,6 +89,7 @@ struct dw_i2c_dev { u32 master_cfg; unsigned int tx_fifo_depth; unsigned int rx_fifo_depth; + int rx_outstanding; }; #define ACCESS_SWAP 0x00000001 -- cgit v1.2.3-18-g5258 From 2a2d95e9d6d29e726cc294b65391917ed2e32bf4 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 13 May 2013 00:54:30 +0000 Subject: i2c: designware: always clear interrupts before enabling them If the I2C bus is put to a low power state by an ACPI method it might pull the SDA line low (as its power is removed). Once the bus is put to full power state again, the SDA line is pulled back to high. This transition looks like a STOP condition from the controller point-of-view which sets STOP detected bit in its status register causing the driver to fail subsequent transfers. Fix this by always clearing all interrupts before we start a transfer. Signed-off-by: Mika Westerberg Signed-off-by: Wolfram Sang Cc: stable@kernel.org --- drivers/i2c/busses/i2c-designware-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index 1f06c8e9934..c41ca6354fc 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -383,7 +383,8 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) /* Enable the adapter */ __i2c_dw_enable(dev, true); - /* Enable interrupts */ + /* Clear and enable interrupts */ + i2c_dw_clear_int(dev); dw_writel(dev, DW_IC_INTR_DEFAULT_MASK, DW_IC_INTR_MASK); } -- cgit v1.2.3-18-g5258 From 5a7e6bd809ca2f06bd669bd477ad3d6b48a3dd9f Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 13 May 2013 00:54:31 +0000 Subject: i2c: designware: add Intel BayTrail ACPI ID This is the same controller as on Intel Lynxpoint but the ACPI ID is different (8086F41). Add support for this. Signed-off-by: Mika Westerberg Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-designware-platdrv.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 8ec91335d95..35b70a1edf5 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -69,6 +69,7 @@ static int dw_i2c_acpi_configure(struct platform_device *pdev) static const struct acpi_device_id dw_i2c_acpi_match[] = { { "INT33C2", 0 }, { "INT33C3", 0 }, + { "80860F41", 0 }, { } }; MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match); -- cgit v1.2.3-18-g5258 From 53229345502bf3713cce220e849743f83065381d Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Wed, 15 May 2013 02:44:10 +0000 Subject: i2c: i801: Document feature bits in modinfo Duplicate the feature bits documentation in modinfo, as not every user will read the driver's source code or documentation file. Signed-off-by: Jean Delvare Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-i801.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index e1cf2e0e1f2..3a6903f6391 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -231,7 +231,11 @@ static const char *i801_feature_names[] = { static unsigned int disable_features; module_param(disable_features, uint, S_IRUGO | S_IWUSR); -MODULE_PARM_DESC(disable_features, "Disable selected driver features"); +MODULE_PARM_DESC(disable_features, "Disable selected driver features:\n" + "\t\t 0x01 disable SMBus PEC\n" + "\t\t 0x02 disable the block buffer\n" + "\t\t 0x08 disable the I2C block read functionality\n" + "\t\t 0x10 don't use interrupts "); /* Make sure the SMBus host is ready to start transmitting. Return 0 if it is, -EBUSY if it is not. */ -- cgit v1.2.3-18-g5258 From d295a86eab200b3f0c513e78dbe1f189fd32d397 Mon Sep 17 00:00:00 2001 From: Russell King Date: Thu, 16 May 2013 10:30:59 +0000 Subject: i2c: mv64xxx: work around signals causing I2C transactions to be aborted Do not use interruptible waits in an I2C driver; if a process uses signals (eg, Xorg uses SIGALRM and SIGPIPE) then these signals can cause the I2C driver to abort a transaction in progress by another driver, which can cause that driver to fail. I2C drivers are not expected to abort transactions on signals. Signed-off-by: Russell King Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-mv64xxx.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c index 3bbd65d35a5..1a3abd6a0bf 100644 --- a/drivers/i2c/busses/i2c-mv64xxx.c +++ b/drivers/i2c/busses/i2c-mv64xxx.c @@ -252,7 +252,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) writel(drv_data->cntl_bits, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); drv_data->block = 0; - wake_up_interruptible(&drv_data->waitq); + wake_up(&drv_data->waitq); break; case MV64XXX_I2C_ACTION_CONTINUE: @@ -300,7 +300,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); drv_data->block = 0; - wake_up_interruptible(&drv_data->waitq); + wake_up(&drv_data->waitq); break; case MV64XXX_I2C_ACTION_INVALID: @@ -315,7 +315,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data) writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP, drv_data->reg_base + MV64XXX_I2C_REG_CONTROL); drv_data->block = 0; - wake_up_interruptible(&drv_data->waitq); + wake_up(&drv_data->waitq); break; } } @@ -381,7 +381,7 @@ mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data) unsigned long flags; char abort = 0; - time_left = wait_event_interruptible_timeout(drv_data->waitq, + time_left = wait_event_timeout(drv_data->waitq, !drv_data->block, drv_data->adapter.timeout); spin_lock_irqsave(&drv_data->lock, flags); -- cgit v1.2.3-18-g5258 From e9b526fe704812364bca07edd15eadeba163ebfb Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Fri, 17 May 2013 14:56:35 +0200 Subject: i2c: suppress lockdep warning on delete_device i2c: suppress lockdep warning on delete_device Since commit 846f99749ab68bbc7f75c74fec305de675b1a1bf the following lockdep warning is thrown in case i2c device is removed (via delete_device sysfs attribute) which contains subdevices (e.g. i2c multiplexer): ============================================= [ INFO: possible recursive locking detected ] 3.8.7-0-sampleversion-fct #8 Tainted: G O --------------------------------------------- bash/3743 is trying to acquire lock: (s_active#110){++++.+}, at: [] sysfs_hash_and_remove+0x58/0xc8 but task is already holding lock: (s_active#110){++++.+}, at: [] sysfs_write_file+0xc8/0x208 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(s_active#110); lock(s_active#110); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by bash/3743: #0: (&buffer->mutex){+.+.+.}, at: [] sysfs_write_file+0x4c/0x208 #1: (s_active#110){++++.+}, at: [] sysfs_write_file+0xc8/0x208 #2: (&adap->userspace_clients_lock/1){+.+.+.}, at: [] i2c_sysfs_delete_device+0x90/0x238 #3: (&__lockdep_no_validate__){......}, at: [] device_release_driver+0x24/0x48 stack backtrace: Call Trace: [] dump_stack+0x8/0x34 [] __lock_acquire+0x161c/0x2110 [] lock_acquire+0x4c/0x70 [] sysfs_addrm_finish+0x19c/0x1e0 [] sysfs_hash_and_remove+0x58/0xc8 [] sysfs_remove_group+0x64/0x148 [] device_remove_attrs+0x9c/0x1a8 [] device_del+0x104/0x1d8 [] device_unregister+0x28/0x70 [] i2c_del_adapter+0x1cc/0x328 [] i2c_del_mux_adapter+0x14/0x38 [] pca954x_remove+0x90/0xe0 [pca954x] [] i2c_device_remove+0x80/0xe8 [] __device_release_driver+0x74/0xf8 [] device_release_driver+0x2c/0x48 [] bus_remove_device+0x13c/0x1d8 [] device_del+0x10c/0x1d8 [] device_unregister+0x28/0x70 [] i2c_sysfs_delete_device+0x180/0x238 [] sysfs_write_file+0xe4/0x208 [] vfs_write+0xbc/0x160 [] SyS_write+0x54/0xd8 [] handle_sys64+0x44/0x64 The problem is already known for USB and PCI subsystems. The reason is that delete_device attribute is defined statically in i2c-core.c and used for all devices in i2c subsystem. Discussion of original USB problem: http://lkml.indiana.edu/hypermail/linux/kernel/1204.3/01160.html Commit 356c05d58af05d582e634b54b40050c73609617b introduced new macro to suppress lockdep warnings for this special case and included workaround for USB code. LKML discussion of the workaround: http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/03634.html As i2c case is in principle the same, the same workaround could be used here. Signed-off-by: Alexander Sverdlin Acked-by: Alan Stern Cc: Eric W. Biederman Cc: Tejun Heo Cc: Peter Zijlstra Cc: Greg Kroah-Hartman Signed-off-by: Wolfram Sang --- drivers/i2c/i2c-core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 6b63cc7eb71..48e31ed69db 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -892,7 +892,8 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); -static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device); +static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, + i2c_sysfs_delete_device); static struct attribute *i2c_adapter_attrs[] = { &dev_attr_name.attr, -- cgit v1.2.3-18-g5258