Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753399AbcJKKNy (ORCPT ); Tue, 11 Oct 2016 06:13:54 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:56879 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752921AbcJKKLj (ORCPT ); Tue, 11 Oct 2016 06:11:39 -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?= , Mauro Carvalho Chehab Subject: [PATCH v2 17/31] dtv5100: don't do DMA on stack Date: Tue, 11 Oct 2016 07:09:32 -0300 Message-Id: <3260d77a7bb7b9da47b5413325a5253e3f5b9e6e.1476179975.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: 1761 Lines: 55 From: Mauro Carvalho Chehab 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 Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/dvb-usb/dtv5100.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/media/usb/dvb-usb/dtv5100.c b/drivers/media/usb/dvb-usb/dtv5100.c index 3d11df41cac0..c60fb54f445f 100644 --- a/drivers/media/usb/dvb-usb/dtv5100.c +++ b/drivers/media/usb/dvb-usb/dtv5100.c @@ -31,9 +31,14 @@ module_param_named(debug, dvb_usb_dtv5100_debug, int, 0644); MODULE_PARM_DESC(debug, "set debugging level" DVB_USB_DEBUG_STATUS); DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr); +struct dtv5100_state { + unsigned char data[80]; +}; + static int dtv5100_i2c_msg(struct dvb_usb_device *d, u8 addr, u8 *wbuf, u16 wlen, u8 *rbuf, u16 rlen) { + struct dtv5100_state *st = d->priv; u8 request; u8 type; u16 value; @@ -60,9 +65,10 @@ static int dtv5100_i2c_msg(struct dvb_usb_device *d, u8 addr, } index = (addr << 8) + wbuf[0]; + memcpy(st->data, rbuf, rlen); msleep(1); /* avoid I2C errors */ return usb_control_msg(d->udev, usb_rcvctrlpipe(d->udev, 0), request, - type, value, index, rbuf, rlen, + type, value, index, st->data, rlen, DTV5100_USB_TIMEOUT); } @@ -176,7 +182,7 @@ static struct dvb_usb_device_properties dtv5100_properties = { .caps = DVB_USB_IS_AN_I2C_ADAPTER, .usb_ctrl = DEVICE_SPECIFIC, - .size_of_priv = 0, + .size_of_priv = sizeof(struct dtv5100_state), .num_adapters = 1, .adapter = {{ -- 2.7.4