| From 5165da5923d6c7df6f2927b0113b2e4d9288661e Mon Sep 17 00:00:00 2001 |
| From: Sebastian Reichel <sebastian.reichel@collabora.co.uk> |
| Date: Fri, 5 May 2017 11:06:50 +0200 |
| Subject: i2c: i2c-tiny-usb: fix buffer not being DMA capable |
| |
| From: Sebastian Reichel <sebastian.reichel@collabora.co.uk> |
| |
| commit 5165da5923d6c7df6f2927b0113b2e4d9288661e upstream. |
| |
| Since v4.9 i2c-tiny-usb generates the below call trace |
| and longer works, since it can't communicate with the |
| USB device. The reason is, that since v4.9 the USB |
| stack checks, that the buffer it should transfer is DMA |
| capable. This was a requirement since v2.2 days, but it |
| usually worked nevertheless. |
| |
| [ 17.504959] ------------[ cut here ]------------ |
| [ 17.505488] WARNING: CPU: 0 PID: 93 at drivers/usb/core/hcd.c:1587 usb_hcd_map_urb_for_dma+0x37c/0x570 |
| [ 17.506545] transfer buffer not dma capable |
| [ 17.507022] Modules linked in: |
| [ 17.507370] CPU: 0 PID: 93 Comm: i2cdetect Not tainted 4.11.0-rc8+ #10 |
| [ 17.508103] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 |
| [ 17.509039] Call Trace: |
| [ 17.509320] ? dump_stack+0x5c/0x78 |
| [ 17.509714] ? __warn+0xbe/0xe0 |
| [ 17.510073] ? warn_slowpath_fmt+0x5a/0x80 |
| [ 17.510532] ? nommu_map_sg+0xb0/0xb0 |
| [ 17.510949] ? usb_hcd_map_urb_for_dma+0x37c/0x570 |
| [ 17.511482] ? usb_hcd_submit_urb+0x336/0xab0 |
| [ 17.511976] ? wait_for_completion_timeout+0x12f/0x1a0 |
| [ 17.512549] ? wait_for_completion_timeout+0x65/0x1a0 |
| [ 17.513125] ? usb_start_wait_urb+0x65/0x160 |
| [ 17.513604] ? usb_control_msg+0xdc/0x130 |
| [ 17.514061] ? usb_xfer+0xa4/0x2a0 |
| [ 17.514445] ? __i2c_transfer+0x108/0x3c0 |
| [ 17.514899] ? i2c_transfer+0x57/0xb0 |
| [ 17.515310] ? i2c_smbus_xfer_emulated+0x12f/0x590 |
| [ 17.515851] ? _raw_spin_unlock_irqrestore+0x11/0x20 |
| [ 17.516408] ? i2c_smbus_xfer+0x125/0x330 |
| [ 17.516876] ? i2c_smbus_xfer+0x125/0x330 |
| [ 17.517329] ? i2cdev_ioctl_smbus+0x1c1/0x2b0 |
| [ 17.517824] ? i2cdev_ioctl+0x75/0x1c0 |
| [ 17.518248] ? do_vfs_ioctl+0x9f/0x600 |
| [ 17.518671] ? vfs_write+0x144/0x190 |
| [ 17.519078] ? SyS_ioctl+0x74/0x80 |
| [ 17.519463] ? entry_SYSCALL_64_fastpath+0x1e/0xad |
| [ 17.519959] ---[ end trace d047c04982f5ac50 ]--- |
| |
| Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk> |
| Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Acked-by: Till Harbaum <till@harbaum.org> |
| Signed-off-by: Wolfram Sang <wsa@the-dreams.de> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/i2c/busses/i2c-tiny-usb.c | 25 +++++++++++++++++++++---- |
| 1 file changed, 21 insertions(+), 4 deletions(-) |
| |
| --- a/drivers/i2c/busses/i2c-tiny-usb.c |
| +++ b/drivers/i2c/busses/i2c-tiny-usb.c |
| @@ -178,22 +178,39 @@ static int usb_read(struct i2c_adapter * |
| int value, int index, void *data, int len) |
| { |
| struct i2c_tiny_usb *dev = (struct i2c_tiny_usb *)adapter->algo_data; |
| + void *dmadata = kmalloc(len, GFP_KERNEL); |
| + int ret; |
| + |
| + if (!dmadata) |
| + return -ENOMEM; |
| |
| /* do control transfer */ |
| - return usb_control_msg(dev->usb_dev, usb_rcvctrlpipe(dev->usb_dev, 0), |
| + ret = usb_control_msg(dev->usb_dev, usb_rcvctrlpipe(dev->usb_dev, 0), |
| cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE | |
| - USB_DIR_IN, value, index, data, len, 2000); |
| + USB_DIR_IN, value, index, dmadata, len, 2000); |
| + |
| + memcpy(data, dmadata, len); |
| + kfree(dmadata); |
| + return ret; |
| } |
| |
| static int usb_write(struct i2c_adapter *adapter, int cmd, |
| int value, int index, void *data, int len) |
| { |
| struct i2c_tiny_usb *dev = (struct i2c_tiny_usb *)adapter->algo_data; |
| + void *dmadata = kmemdup(data, len, GFP_KERNEL); |
| + int ret; |
| + |
| + if (!dmadata) |
| + return -ENOMEM; |
| |
| /* do control transfer */ |
| - return usb_control_msg(dev->usb_dev, usb_sndctrlpipe(dev->usb_dev, 0), |
| + ret = usb_control_msg(dev->usb_dev, usb_sndctrlpipe(dev->usb_dev, 0), |
| cmd, USB_TYPE_VENDOR | USB_RECIP_INTERFACE, |
| - value, index, data, len, 2000); |
| + value, index, dmadata, len, 2000); |
| + |
| + kfree(dmadata); |
| + return ret; |
| } |
| |
| static void i2c_tiny_usb_free(struct i2c_tiny_usb *dev) |