HID: cp2112: support large i2c transfers
cp2112_i2c_xfer() only reads up to 61 bytes, returning EIO on longers reads. The fix is to wrap a loop around cp2112_read() to pick up all the returned data. Signed-off-by: Ellen Wang <ellen@cumulusnetworks.com> Signed-off-by: Jiri Kosina <jkosina@suse.com>
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@ -511,13 +511,30 @@ static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
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if (!(msgs->flags & I2C_M_RD))
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goto finish;
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ret = cp2112_read(dev, msgs->buf, msgs->len);
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if (ret < 0)
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goto power_normal;
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if (ret != msgs->len) {
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hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len);
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ret = -EIO;
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goto power_normal;
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for (count = 0; count < msgs->len;) {
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ret = cp2112_read(dev, msgs->buf + count, msgs->len - count);
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if (ret < 0)
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goto power_normal;
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if (ret == 0) {
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hid_err(hdev, "read returned 0\n");
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ret = -EIO;
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goto power_normal;
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}
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count += ret;
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if (count > msgs->len) {
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/*
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* The hardware returned too much data.
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* This is mostly harmless because cp2112_read()
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* has a limit check so didn't overrun our
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* buffer. Nevertheless, we return an error
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* because something is seriously wrong and
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* it shouldn't go unnoticed.
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*/
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hid_err(hdev, "long read: %d > %zd\n",
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ret, msgs->len - count + ret);
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ret = -EIO;
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goto power_normal;
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}
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}
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finish:
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