Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752586AbcJJGkM (ORCPT ); Mon, 10 Oct 2016 02:40:12 -0400 Received: from mout02.posteo.de ([185.67.36.66]:35007 "EHLO mout02.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752316AbcJJGkJ (ORCPT ); Mon, 10 Oct 2016 02:40:09 -0400 Date: Mon, 10 Oct 2016 08:37:31 +0200 From: Patrick Boettcher To: Mauro Carvalho Chehab Cc: Linux Media Mailing List , Mauro Carvalho Chehab , Andy Lutomirski , Johannes Stezenbach , Jiri Kosina , Linux Kernel Mailing List , Andy Lutomirski , Michael Krufky , Mauro Carvalho Chehab , =?UTF-8?B?SsO2cmc=?= Otte , Arnd Bergmann Subject: Re: [PATCH 09/26] dibusb: don't do DMA on stack Message-ID: <20161010083731.0efad775@posteo.de> In-Reply-To: <801c76677194f958a58622129df3a0fcd59a5447.1475860773.git.mchehab@s-opensource.com> References: <801c76677194f958a58622129df3a0fcd59a5447.1475860773.git.mchehab@s-opensource.com> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5921 Lines: 216 On Fri, 7 Oct 2016 14:24:19 -0300 Mauro Carvalho Chehab wrote: > 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/dibusb-common.c | 106 > +++++++++++++++++++++--------- > drivers/media/usb/dvb-usb/dibusb.h | 5 ++ 2 files changed, > 81 insertions(+), 30 deletions(-) > > diff --git a/drivers/media/usb/dvb-usb/dibusb-common.c > b/drivers/media/usb/dvb-usb/dibusb-common.c index > 4b08c2a47ae2..76b26dc7339c 100644 --- > a/drivers/media/usb/dvb-usb/dibusb-common.c +++ > b/drivers/media/usb/dvb-usb/dibusb-common.c @@ -12,9 +12,6 @@ > #include > #include "dibusb.h" > > -/* Max transfer size done by I2C transfer functions */ > -#define MAX_XFER_SIZE 64 > - > static int debug; > module_param(debug, int, 0644); > MODULE_PARM_DESC(debug, "set debugging level (1=info (|-able))." > DVB_USB_DEBUG_STATUS); @@ -63,72 +60,109 @@ > EXPORT_SYMBOL(dibusb_pid_filter_ctrl); > int dibusb_power_ctrl(struct dvb_usb_device *d, int onoff) > { > - u8 b[3]; > + u8 *b; > int ret; > + > + b = kmalloc(3, GFP_KERNEL); > + if (!b) > + return -ENOMEM; > + > b[0] = DIBUSB_REQ_SET_IOCTL; > b[1] = DIBUSB_IOCTL_CMD_POWER_MODE; > b[2] = onoff ? DIBUSB_IOCTL_POWER_WAKEUP : > DIBUSB_IOCTL_POWER_SLEEP; > - ret = dvb_usb_generic_write(d,b,3); > + > + ret = dvb_usb_generic_write(d, b, 3); > + > + kfree(b); > + > msleep(10); > + > return ret; > } > EXPORT_SYMBOL(dibusb_power_ctrl); > > int dibusb2_0_streaming_ctrl(struct dvb_usb_adapter *adap, int onoff) > { > - u8 b[3] = { 0 }; > + struct dibusb_state *st = adap->priv; > int ret; > > if ((ret = dibusb_streaming_ctrl(adap,onoff)) < 0) > return ret; > > if (onoff) { > - b[0] = DIBUSB_REQ_SET_STREAMING_MODE; > - b[1] = 0x00; > - if ((ret = dvb_usb_generic_write(adap->dev,b,2)) < 0) > + st->data[0] = DIBUSB_REQ_SET_STREAMING_MODE; > + st->data[1] = 0x00; > + ret = dvb_usb_generic_write(adap->dev, st->data, 2); > + if (ret < 0) > return ret; > } > > - b[0] = DIBUSB_REQ_SET_IOCTL; > - b[1] = onoff ? DIBUSB_IOCTL_CMD_ENABLE_STREAM : > DIBUSB_IOCTL_CMD_DISABLE_STREAM; > - return dvb_usb_generic_write(adap->dev,b,3); > + st->data[0] = DIBUSB_REQ_SET_IOCTL; > + st->data[1] = onoff ? DIBUSB_IOCTL_CMD_ENABLE_STREAM : > DIBUSB_IOCTL_CMD_DISABLE_STREAM; > + return dvb_usb_generic_write(adap->dev, st->data, 3); > } > EXPORT_SYMBOL(dibusb2_0_streaming_ctrl); > > int dibusb2_0_power_ctrl(struct dvb_usb_device *d, int onoff) > { > - if (onoff) { > - u8 b[3] = { DIBUSB_REQ_SET_IOCTL, > DIBUSB_IOCTL_CMD_POWER_MODE, DIBUSB_IOCTL_POWER_WAKEUP }; > - return dvb_usb_generic_write(d,b,3); > - } else > + u8 *b; > + int ret; > + > + if (!onoff) > return 0; > + > + b = kmalloc(3, GFP_KERNEL); > + if (!b) > + return -ENOMEM; > + > + b[0] = DIBUSB_REQ_SET_IOCTL; > + b[1] = DIBUSB_IOCTL_CMD_POWER_MODE; > + b[2] = DIBUSB_IOCTL_POWER_WAKEUP; > + > + ret = dvb_usb_generic_write(d, b, 3); > + > + kfree(b); > + > + return ret; > } > EXPORT_SYMBOL(dibusb2_0_power_ctrl); > > static int dibusb_i2c_msg(struct dvb_usb_device *d, u8 addr, > u8 *wbuf, u16 wlen, u8 *rbuf, u16 rlen) > { > - u8 sndbuf[MAX_XFER_SIZE]; /* lead(1) devaddr,direction(1) > addr(2) data(wlen) (len(2) (when reading)) */ > + u8 *sndbuf; > + int ret, wo, len; > + > /* write only ? */ > - int wo = (rbuf == NULL || rlen == 0), > - len = 2 + wlen + (wo ? 0 : 2); > + wo = (rbuf == NULL || rlen == 0); > > - if (4 + wlen > sizeof(sndbuf)) { > + len = 2 + wlen + (wo ? 0 : 2); > + > + sndbuf = kmalloc(MAX_XFER_SIZE, GFP_KERNEL); > + if (!sndbuf) > + return -ENOMEM; > + > + if (4 + wlen > MAX_XFER_SIZE) { > warn("i2c wr: len=%d is too big!\n", wlen); > - return -EOPNOTSUPP; > + ret = -EOPNOTSUPP; > + goto ret; > } > > sndbuf[0] = wo ? DIBUSB_REQ_I2C_WRITE : DIBUSB_REQ_I2C_READ; > sndbuf[1] = (addr << 1) | (wo ? 0 : 1); > > - memcpy(&sndbuf[2],wbuf,wlen); > + memcpy(&sndbuf[2], wbuf, wlen); > > if (!wo) { > - sndbuf[wlen+2] = (rlen >> 8) & 0xff; > - sndbuf[wlen+3] = rlen & 0xff; > + sndbuf[wlen + 2] = (rlen >> 8) & 0xff; > + sndbuf[wlen + 3] = rlen & 0xff; > } > > - return dvb_usb_generic_rw(d,sndbuf,len,rbuf,rlen,0); > + ret = dvb_usb_generic_rw(d, sndbuf, len, rbuf, rlen, 0); > + > +ret: > + kfree(sndbuf); > + return ret; > } > > /* > @@ -320,11 +354,23 @@ EXPORT_SYMBOL(rc_map_dibusb_table); > > int dibusb_rc_query(struct dvb_usb_device *d, u32 *event, int *state) > { > - u8 key[5],cmd = DIBUSB_REQ_POLL_REMOTE; > - dvb_usb_generic_rw(d,&cmd,1,key,5,0); > - dvb_usb_nec_rc_key_to_event(d,key,event,state); > - if (key[0] != 0) > - deb_info("key: %*ph\n", 5, key); > + u8 *buf; > + > + buf = kmalloc(5, GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + buf[0] = DIBUSB_REQ_POLL_REMOTE; > + > + dvb_usb_generic_rw(d, buf, 1, buf, 5, 0); > + > + dvb_usb_nec_rc_key_to_event(d, buf, event, state); > + > + if (buf[0] != 0) > + deb_info("key: %*ph\n", 5, buf); > + > + kfree(buf); > + > return 0; > } > EXPORT_SYMBOL(dibusb_rc_query); > diff --git a/drivers/media/usb/dvb-usb/dibusb.h > b/drivers/media/usb/dvb-usb/dibusb.h index 3f82163d8ab8..42e9750393e5 > 100644 --- a/drivers/media/usb/dvb-usb/dibusb.h > +++ b/drivers/media/usb/dvb-usb/dibusb.h > @@ -96,10 +96,15 @@ > #define DIBUSB_IOCTL_CMD_ENABLE_STREAM 0x01 > #define DIBUSB_IOCTL_CMD_DISABLE_STREAM 0x02 > > +/* Max transfer size done by I2C transfer functions */ > +#define MAX_XFER_SIZE 64 > + > struct dibusb_state { > struct dib_fe_xfer_ops ops; > int mt2060_present; > u8 tuner_addr; > + > + unsigned char data[MAX_XFER_SIZE]; > }; > > struct dibusb_device_state { Reviewed-By: Patrick Boettcher