From: Frank Rowand <frank.row...@am.sony.com>
Commit 3a878c430fd6 ("tty: serial: msm: Add TX DMA support") regression.
The calculation of tx_count was moved from the old msm_handle_tx(),
now renamed msm_handle_tx_pio(), to the new msm_handle_tx(). The
move left out one size test.
The regression seen on the qcom-apq8074-dragonboard is dropped
characters and corrupted characters (values greater than 0x7f)
when DMA is not enabled.
Signed-off-by: Frank Rowand <frank.row...@am.sony.com>
Cc: sta...@vger.kernel.org
---
drivers/tty/serial/msm_serial.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
Index: b/drivers/tty/serial/msm_serial.c
===================================================================
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -727,6 +727,8 @@ static void msm_handle_tx(struct uart_po
}
pio_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
+ pio_count = min3(pio_count, (unsigned int)UART_XMIT_SIZE - xmit->tail,
+ port->fifosize);
dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
dma_min = 1; /* Always DMA */
@@ -738,9 +740,6 @@ static void msm_handle_tx(struct uart_po
dma_count = UARTDM_TX_MAX;
}
- if (pio_count > port->fifosize)
- pio_count = port->fifosize;
-
if (!dma->chan || dma_count < dma_min)
msm_handle_tx_pio(port, pio_count);
else
