spi-topcliff-pch: Fix CPU read complete condition issue

We found Rx data sometimes drops.(with non-DMA transfer mode)
The cause is read complete condition is not true.

This patch fixes the issue.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index c36d516570666c7a6767b89c80d4a5f2e574928d..6cb2fdbe5dba84d8c05b16d899d52704313a40d9 100644 (file)
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -317,16 +317,19 @@ static void pch_spi_handler_sub(struct pch_spi_data *data, u32 reg_spsr_val,
 
        /* if transfer complete interrupt */
        if (reg_spsr_val & SPSR_FI_BIT) {
-               if (tx_index < bpw_len)
+               if ((tx_index == bpw_len) && (rx_index == tx_index)) {
+                       /* disable interrupts */
+                       pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
+
+                       /* transfer is completed;
+                          inform pch_spi_process_messages */
+                       data->transfer_complete = true;
+                       data->transfer_active = false;
+                       wake_up(&data->wait);
+               } else {
                        dev_err(&data->master->dev,
                                "%s : Transfer is not completed", __func__);
-               /* disable interrupts */
-               pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
-
-               /* transfer is completed;inform pch_spi_process_messages */
-               data->transfer_complete = true;
-               data->transfer_active = false;
-               wake_up(&data->wait);
+               }
        }
 }