diff options
| -rw-r--r-- | drivers/hid/hid-ft260.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/drivers/hid/hid-ft260.c b/drivers/hid/hid-ft260.c index 946ed0c6fc39..64c9c940db46 100644 --- a/drivers/hid/hid-ft260.c +++ b/drivers/hid/hid-ft260.c @@ -240,6 +240,8 @@ struct ft260_device { struct mutex lock; u8 write_buf[FT260_REPORT_MAX_LENGTH]; unsigned long need_wakeup_at; + /* Protects read_buf, read_idx and read_len against ft260_raw_event() */ + spinlock_t read_lock; u8 *read_buf; u16 read_idx; u16 read_len; @@ -501,6 +503,7 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, int timeout, ret = 0; struct ft260_i2c_read_request_report rep; struct hid_device *hdev = dev->hdev; + unsigned long irqflags; u8 bus_busy = 0; /* * STOP terminates the last chunk; clear means hold the bus so a @@ -534,9 +537,11 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, reinit_completion(&dev->wait); + spin_lock_irqsave(&dev->read_lock, irqflags); dev->read_idx = 0; dev->read_buf = data; dev->read_len = rd_len; + spin_unlock_irqrestore(&dev->read_lock, irqflags); ret = ft260_hid_output_report(hdev, (u8 *)&rep, sizeof(rep)); if (ret < 0) { @@ -551,7 +556,9 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, goto ft260_i2c_read_exit; } + spin_lock_irqsave(&dev->read_lock, irqflags); dev->read_buf = NULL; + spin_unlock_irqrestore(&dev->read_lock, irqflags); if (flag & FT260_FLAG_STOP) bus_busy = FT260_I2C_STATUS_BUS_BUSY; @@ -570,7 +577,9 @@ static int ft260_i2c_read(struct ft260_device *dev, u8 addr, u8 *data, } while (len > 0); ft260_i2c_read_exit: + spin_lock_irqsave(&dev->read_lock, irqflags); dev->read_buf = NULL; + spin_unlock_irqrestore(&dev->read_lock, irqflags); return ret; } @@ -1053,6 +1062,7 @@ static int ft260_probe(struct hid_device *hdev, const struct hid_device_id *id) "FT260 usb-i2c bridge"); mutex_init(&dev->lock); + spin_lock_init(&dev->read_lock); init_completion(&dev->wait); ret = ft260_xfer_status(dev, FT260_I2C_STATUS_BUS_BUSY); @@ -1102,6 +1112,7 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report, { struct ft260_device *dev = hid_get_drvdata(hdev); struct ft260_i2c_input_report *xfer = (void *)data; + unsigned long irqflags; if (size < offsetof(struct ft260_i2c_input_report, data)) { hid_err(hdev, "short report %d\n", size); @@ -1110,6 +1121,8 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report, if (xfer->report >= FT260_I2C_REPORT_MIN && xfer->report <= FT260_I2C_REPORT_MAX) { + bool complete_read; + ft260_dbg("i2c resp: rep %#02x len %d size %d\n", xfer->report, xfer->length, size); @@ -1120,8 +1133,15 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report, return -1; } + /* + * Hold read_lock so a timed-out ft260_i2c_read() cannot + * clear read_buf between the NULL check and the memcpy. + */ + spin_lock_irqsave(&dev->read_lock, irqflags); + if ((dev->read_buf == NULL) || (xfer->length > dev->read_len - dev->read_idx)) { + spin_unlock_irqrestore(&dev->read_lock, irqflags); hid_err(hdev, "unexpected report %#02x, length %d\n", xfer->report, xfer->length); return -1; @@ -1130,8 +1150,11 @@ static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report, memcpy(&dev->read_buf[dev->read_idx], &xfer->data, xfer->length); dev->read_idx += xfer->length; + complete_read = dev->read_idx == dev->read_len; + + spin_unlock_irqrestore(&dev->read_lock, irqflags); - if (dev->read_idx == dev->read_len) + if (complete_read) complete(&dev->wait); } else { |