3.3-stable review patch. If anyone has any objections, please let me know.
------------------ From: Tomoya MORINAGA <[email protected]> commit af6d17cdc8c89aeb3101f0d27cd32fc0592b40b2 upstream. This driver anticipates pch_uart_verify_port() is not called during installation. However, actually pch_uart_verify_port() is called during installation. As a result, memory access violation occurs like below. 0. initial value: use_dma=0 1. starup() - dma channel is not allocated because use_dma=0 2. pch_uart_verify_port() - Set use_dma=1 3. UART processing acts DMA mode because use_dma=1 - memory access violation occurs! This patch fixes the issue. Solution: Whenever pch_uart_verify_port() is called and then dma channel is not allocated, the channel should be allocated. Signed-off-by: Tomoya MORINAGA <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/tty/serial/pch_uart.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -1366,9 +1366,11 @@ static int pch_uart_verify_port(struct u __func__); return -EOPNOTSUPP; #endif - priv->use_dma = 1; priv->use_dma_flag = 1; dev_info(priv->port.dev, "PCH UART : Use DMA Mode\n"); + if (!priv->use_dma) + pch_request_dma(port); + priv->use_dma = 1; } return 0; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
