Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965322AbcJGR14 (ORCPT ); Fri, 7 Oct 2016 13:27:56 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:46773 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S938880AbcJGRYq (ORCPT ); Fri, 7 Oct 2016 13:24:46 -0400 From: Mauro Carvalho Chehab To: Linux Media Mailing List Cc: Mauro Carvalho Chehab , Mauro Carvalho Chehab , Andy Lutomirski , Johannes Stezenbach , Jiri Kosina , Patrick Boettcher , Linux Kernel Mailing List , Andy Lutomirski , Michael Krufky , Mauro Carvalho Chehab , =?UTF-8?q?J=C3=B6rg=20Otte?= Subject: [PATCH 06/26] cxusb: don't do DMA on stack Date: Fri, 7 Oct 2016 14:24:16 -0300 Message-Id: <7727b11abd004f683589586082f1b00926d5dade.1475860773.git.mchehab@s-opensource.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2319 Lines: 78 The USB control messages require DMA to work. We cannot pass a stack-allocated buffer, as it is not warranted that the stack would be into a DMA enabled area. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/dvb-usb/cxusb.c | 20 +++++++------------- drivers/media/usb/dvb-usb/cxusb.h | 5 +++++ 2 files changed, 12 insertions(+), 13 deletions(-) diff --git a/drivers/media/usb/dvb-usb/cxusb.c b/drivers/media/usb/dvb-usb/cxusb.c index 907ac01ae297..f3615349de52 100644 --- a/drivers/media/usb/dvb-usb/cxusb.c +++ b/drivers/media/usb/dvb-usb/cxusb.c @@ -45,9 +45,6 @@ #include "si2168.h" #include "si2157.h" -/* Max transfer size done by I2C transfer functions */ -#define MAX_XFER_SIZE 80 - /* debug */ static int dvb_usb_cxusb_debug; module_param_named(debug, dvb_usb_cxusb_debug, int, 0644); @@ -61,23 +58,20 @@ DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr); static int cxusb_ctrl_msg(struct dvb_usb_device *d, u8 cmd, u8 *wbuf, int wlen, u8 *rbuf, int rlen) { + struct cxusb_state *st = d->priv; int wo = (rbuf == NULL || rlen == 0); /* write-only */ - u8 sndbuf[MAX_XFER_SIZE]; - if (1 + wlen > sizeof(sndbuf)) { - warn("i2c wr: len=%d is too big!\n", - wlen); + if (1 + wlen > MAX_XFER_SIZE) { + warn("i2c wr: len=%d is too big!\n", wlen); return -EOPNOTSUPP; } - memset(sndbuf, 0, 1+wlen); - - sndbuf[0] = cmd; - memcpy(&sndbuf[1], wbuf, wlen); + st->data[0] = cmd; + memcpy(&st->data[1], wbuf, wlen); if (wo) - return dvb_usb_generic_write(d, sndbuf, 1+wlen); + return dvb_usb_generic_write(d, st->data, 1 + wlen); else - return dvb_usb_generic_rw(d, sndbuf, 1+wlen, rbuf, rlen, 0); + return dvb_usb_generic_rw(d, st->data, 1 + wlen, rbuf, rlen, 0); } /* GPIO */ diff --git a/drivers/media/usb/dvb-usb/cxusb.h b/drivers/media/usb/dvb-usb/cxusb.h index 527ff7905e15..18acda19527a 100644 --- a/drivers/media/usb/dvb-usb/cxusb.h +++ b/drivers/media/usb/dvb-usb/cxusb.h @@ -28,10 +28,15 @@ #define CMD_ANALOG 0x50 #define CMD_DIGITAL 0x51 +/* Max transfer size done by I2C transfer functions */ +#define MAX_XFER_SIZE 80 + struct cxusb_state { u8 gpio_write_state[3]; struct i2c_client *i2c_client_demod; struct i2c_client *i2c_client_tuner; + + unsigned char data[MAX_XFER_SIZE]; }; #endif -- 2.7.4