evie/android_kernel_oneplus_msm8998
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

USB: f_ccid: Unblock ccid_ctrl_read() during disconnect

Browse source 
Whenever userspace calls read system call for ctrl_dev, ccid driver
waits till it receives control request from host. Once it receives
control data, it unblocks read and passes data to userspace. But if
cable is disconnected, then ccid driver is not unblocking read due
to which next open of ctrl_dev failing. This results in ccid functionality
not working after cable reconnection as userspace not able to open
ctrl_dev. Hence fix the issue by checking for online status and if
online flag is cleared, unblock read and return -ENODEV.

Also align request buffer length to OUT endpoint's max packet size,
when userspace tries to queue buffer length that is not multiple of
OUT endpoint max packet as USB controller expects length multiple of
maxpacket.

Change-Id: I97d1819c21919b6c66b7a1e5fbf1c452ec691639
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
This commit is contained in:
Vijayavardhan Vennapusa 2017-07-27 15:46:55 +05:30
parent e29d253ecf
commit 8d57aea469
1 changed files with 10 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
drivers/usb/gadget/function/f_ccid.c
View file

@ -26,7 +26,7 @@
#include "f_ccid.h"
#define BULK_IN_BUFFER_SIZE sizeof(struct ccid_bulk_in_header)
#define BULK_OUT_BUFFER_SIZE sizeof(struct ccid_bulk_out_header)
#define BULK_OUT_BUFFER_SIZE 1024
#define CTRL_BUF_SIZE 4
#define FUNCTION_NAME "ccid"
#define MAX_INST_NAME_LEN 40
@ -629,14 +629,14 @@ static ssize_t ccid_bulk_read(struct file *fp, char __user *buf,
struct f_ccid *ccid_dev = fp->private_data;
struct ccid_bulk_dev *bulk_dev = &ccid_dev->bulk_dev;
struct usb_request *req;
int r = count, xfer;
int r = count, xfer, len;
int ret;
unsigned long flags;
pr_debug("ccid_bulk_read(%zu)\n", count);
if (count > BULK_OUT_BUFFER_SIZE) {
pr_err("%s: max_buffer_size:%zu given_pkt_size:%zu\n",
pr_err("%s: max_buffer_size:%d given_pkt_size:%zu\n",
__func__, BULK_OUT_BUFFER_SIZE, count);
return -ENOMEM;
}
@ -647,6 +647,7 @@ static ssize_t ccid_bulk_read(struct file *fp, char __user *buf,
goto done;
}
len = ALIGN(count, ccid_dev->out->maxpacket);
requeue_req:
spin_lock_irqsave(&ccid_dev->lock, flags);
if (!atomic_read(&ccid_dev->online)) {
@ -655,7 +656,7 @@ requeue_req:
}
/* queue a request */
req = bulk_dev->rx_req;
req->length = count;
req->length = len;
bulk_dev->rx_done = 0;
spin_unlock_irqrestore(&ccid_dev->lock, flags);
ret = usb_ep_queue(ccid_dev->out, req, GFP_KERNEL);
@ -688,6 +689,9 @@ requeue_req:
spin_unlock_irqrestore(&ccid_dev->lock, flags);
goto requeue_req;
}
if (req->actual > count)
pr_err("%s More data received(%d) than required(%zu)\n",
__func__, req->actual, count);
xfer = (req->actual < count) ? req->actual : count;
atomic_set(&bulk_dev->rx_req_busy, 1);
spin_unlock_irqrestore(&ccid_dev->lock, flags);
@ -875,7 +879,8 @@ static ssize_t ccid_ctrl_read(struct file *fp, char __user *buf,
count = CTRL_BUF_SIZE;
ret = wait_event_interruptible(ctrl_dev->tx_wait_q,
ctrl_dev->tx_ctrl_done);
ctrl_dev->tx_ctrl_done ||
!atomic_read(&ccid_dev->online));
if (ret < 0)
return ret;
ctrl_dev->tx_ctrl_done = 0;