From 965faeecbb68c38599c7914b5fc38b72e8734bb3 Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Thu, 2 Jun 2016 17:48:28 -0700 Subject: [PATCH] tty: serial: msm: Don't read off end of tx fifo For dm uarts in pio mode tx data is transferred to the fifo register 4 bytes at a time, but care is not taken when these 4 bytes spans the end of the xmit buffer so the loop might read up to 3 bytes past the buffer and then skip the actual data at the beginning of the buffer. Fix this by, analogous to the DMA case, make sure the chunk doesn't wrap the xmit buffer. CRs-Fixed: 1053499 Change-Id: Ia6127c3a18e8909171c4b24c633e361245d1ed72 Fixes: 3a878c430fd6 ("tty: serial: msm: Add TX DMA support") Cc: Ivan Ivanov Cc: stable@vger.kernel.org Reported-by: Frank Rowand Reported-by: Nicolas Dechesne Signed-off-by: Bjorn Andersson Acked-by: Andy Gross Tested-by: Frank Rowand Reviewed-by: Stephen Boyd Signed-off-by: Greg Kroah-Hartman Git-commit: 30acf549ca1e81859a67590ab9ecfce3d1050a0b Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git Signed-off-by: Satya Durga Srinivasu Prabhala --- drivers/tty/serial/msm_serial.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index a442270ee0c7..7df1365a7458 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -891,7 +891,7 @@ static void msm_handle_tx(struct uart_port *port) return; } - pio_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE); + pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); dma_min = 1; /* Always DMA */