mei: revamp writing slot counting

Since txe use doorbell and not circular buffer
we have to cheat in write slot counting, txe always consume all the
slots upon write. In order for it to work we need to track
slots using mei_hbuf_empty_slots() instead of tracking it in mei layer

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 13 insertions, 8 deletions

diff --git a/drivers/misc/mei/hw-txe.c b/drivers/misc/mei/hw-txe.c
index 8f5e4be9ebc2..f60182a52f96 100644
--- a/drivers/misc/mei/hw-txe.c
+++ b/drivers/misc/mei/hw-txe.c
@@ -566,7 +566,9 @@ static int mei_txe_write(struct mei_device *dev,
         struct mei_txe_hw *hw = to_txe_hw(dev);
         unsigned long rem;
         unsigned long length;
+        int slots = dev->hbuf_depth;
         u32 *reg_buf = (u32 *)buf;
+        u32 dw_cnt;
         int i;
 
         if (WARN_ON(!header || !buf))
@@ -576,11 +578,9 @@ static int mei_txe_write(struct mei_device *dev,
 
         dev_dbg(&dev->pdev->dev, MEI_HDR_FMT, MEI_HDR_PRM(header));
 
-        if ((length + sizeof(struct mei_msg_hdr)) > PAYLOAD_SIZE) {
-                dev_err(&dev->pdev->dev, "write length exceeded = %ld > %d\n",
-                        length + sizeof(struct mei_msg_hdr), PAYLOAD_SIZE);
-                return -ERANGE;
-        }
+        dw_cnt = mei_data2slots(length);
+        if (dw_cnt > slots)
+                return -EMSGSIZE;
 
         if (WARN(!hw->aliveness, "txe write: aliveness not asserted\n"))
                 return -EAGAIN;
@@ -605,6 +605,9 @@ static int mei_txe_write(struct mei_device *dev,
                 mei_txe_input_payload_write(dev, i + 1, reg);
         }
 
+        /* after each write the whole buffer is consumed */
+        hw->slots = 0;
+
         /* Set Input-Doorbell */
         mei_txe_input_doorbell_set(hw);
 
@@ -632,7 +635,8 @@ static size_t mei_txe_hbuf_max_len(const struct mei_device *dev)
  */
 static int mei_txe_hbuf_empty_slots(struct mei_device *dev)
 {
-        return dev->hbuf_depth;
+        struct mei_txe_hw *hw = to_txe_hw(dev);
+        return hw->slots;
 }
 
 /**
@@ -978,11 +982,12 @@ irqreturn_t mei_txe_irq_thread_handler(int irq, void *dev_id)
                 }
         }
         /* Input Ready: Detection if host can write to SeC */
-        if (test_and_clear_bit(TXE_INTR_IN_READY_BIT, &hw->intr_cause))
+        if (test_and_clear_bit(TXE_INTR_IN_READY_BIT, &hw->intr_cause)) {
                 dev->hbuf_is_ready = true;
+                hw->slots = dev->hbuf_depth;
+        }
 
         if (hw->aliveness && dev->hbuf_is_ready) {
-
                 /* get the real register value */
                 dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
                 rets = mei_irq_write_handler(dev, &complete_list);