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authorSebastian Reichel <sebastian.reichel@collabora.co.uk>2017-05-05 12:06:50 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-06-07 13:10:06 +0300
commit2da7518890d83a7fc94de41f1bcf7d24b9e13fa9 (patch)
tree9622d4a64b22ebeeb71619e6a962e88ebac4fff6
parente4bab31cf957f3b5534e7137ffa6e1267a1e9c00 (diff)
downloadlinux-2da7518890d83a7fc94de41f1bcf7d24b9e13fa9.tar.xz
i2c: i2c-tiny-usb: fix buffer not being DMA capable
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>
-rw-r--r--drivers/i2c/busses/i2c-tiny-usb.c25
1 files changed, 21 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-tiny-usb.c b/drivers/i2c/busses/i2c-tiny-usb.c
index 0ed77eeff31e..a2e3dd715380 100644
--- 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 *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 = 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)