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>

1 files changed, 11 insertions, 8 deletions

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index c36d51657066..6cb2fdbe5dba 100644
--- 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);
+                }
         }
 }