Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753241AbcJKKMc (ORCPT ); Tue, 11 Oct 2016 06:12:32 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:56887 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752999AbcJKKLj (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?= Subject: [PATCH v2 13/31] dtt200u-fe: don't do DMA on stack Date: Tue, 11 Oct 2016 07:09:28 -0300 Message-Id: <15fcc12dc8fe547116decedc20ef87398c640dee.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: 5207 Lines: 188 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/dtt200u-fe.c | 95 +++++++++++++++++++++++----------- 1 file changed, 65 insertions(+), 30 deletions(-) diff --git a/drivers/media/usb/dvb-usb/dtt200u-fe.c b/drivers/media/usb/dvb-usb/dtt200u-fe.c index 9bb15f7b48db..7f7f64be6353 100644 --- a/drivers/media/usb/dvb-usb/dtt200u-fe.c +++ b/drivers/media/usb/dvb-usb/dtt200u-fe.c @@ -18,17 +18,22 @@ struct dtt200u_fe_state { struct dtv_frontend_properties fep; struct dvb_frontend frontend; + + unsigned char data[80]; + struct mutex data_mutex; }; static int dtt200u_fe_read_status(struct dvb_frontend *fe, enum fe_status *stat) { struct dtt200u_fe_state *state = fe->demodulator_priv; - u8 st = GET_TUNE_STATUS, b[3]; - dvb_usb_generic_rw(state->d,&st,1,b,3,0); + mutex_lock(&state->data_mutex); + state->data[0] = GET_TUNE_STATUS; - switch (b[0]) { + dvb_usb_generic_rw(state->d, state->data, 1, state->data, 3, 0); + + switch (state->data[0]) { case 0x01: *stat = FE_HAS_SIGNAL | FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_SYNC | FE_HAS_LOCK; @@ -41,51 +46,75 @@ static int dtt200u_fe_read_status(struct dvb_frontend *fe, *stat = 0; break; } + mutex_unlock(&state->data_mutex); return 0; } static int dtt200u_fe_read_ber(struct dvb_frontend* fe, u32 *ber) { struct dtt200u_fe_state *state = fe->demodulator_priv; - u8 bw = GET_VIT_ERR_CNT,b[3]; - dvb_usb_generic_rw(state->d,&bw,1,b,3,0); - *ber = (b[0] << 16) | (b[1] << 8) | b[2]; + + mutex_lock(&state->data_mutex); + state->data[0] = GET_VIT_ERR_CNT; + + dvb_usb_generic_rw(state->d, state->data, 1, state->data, 3, 0); + *ber = (state->data[0] << 16) | (state->data[1] << 8) | state->data[2]; + + mutex_unlock(&state->data_mutex); return 0; } static int dtt200u_fe_read_unc_blocks(struct dvb_frontend* fe, u32 *unc) { struct dtt200u_fe_state *state = fe->demodulator_priv; - u8 bw = GET_RS_UNCOR_BLK_CNT,b[2]; - dvb_usb_generic_rw(state->d,&bw,1,b,2,0); - *unc = (b[0] << 8) | b[1]; - return 0; + mutex_lock(&state->data_mutex); + state->data[0] = GET_RS_UNCOR_BLK_CNT; + + dvb_usb_generic_rw(state->d, state->data, 1, state->data, 2, 0); + + mutex_unlock(&state->data_mutex); + return ret; } static int dtt200u_fe_read_signal_strength(struct dvb_frontend* fe, u16 *strength) { struct dtt200u_fe_state *state = fe->demodulator_priv; - u8 bw = GET_AGC, b; - dvb_usb_generic_rw(state->d,&bw,1,&b,1,0); - *strength = (b << 8) | b; - return 0; + + mutex_lock(&state->data_mutex); + state->data[0] = GET_AGC; + + dvb_usb_generic_rw(state->d, state->data, 1, state->data, 1, 0); + + mutex_unlock(&state->data_mutex); + return ret; } static int dtt200u_fe_read_snr(struct dvb_frontend* fe, u16 *snr) { struct dtt200u_fe_state *state = fe->demodulator_priv; - u8 bw = GET_SNR,br; - dvb_usb_generic_rw(state->d,&bw,1,&br,1,0); - *snr = ~((br << 8) | br); - return 0; + + mutex_lock(&state->data_mutex); + state->data[0] = GET_SNR; + + dvb_usb_generic_rw(state->d, state->data, 1, state->data, 1, 0); + + mutex_unlock(&state->data_mutex); + return ret; } static int dtt200u_fe_init(struct dvb_frontend* fe) { struct dtt200u_fe_state *state = fe->demodulator_priv; - u8 b = SET_INIT; - return dvb_usb_generic_write(state->d,&b,1); + int ret; + + mutex_lock(&state->data_mutex); + state->data[0] = SET_INIT; + + ret = dvb_usb_generic_write(state->d, state->data, 1); + mutex_unlock(&state->data_mutex); + + return ret; } static int dtt200u_fe_sleep(struct dvb_frontend* fe) @@ -106,29 +135,34 @@ static int dtt200u_fe_set_frontend(struct dvb_frontend *fe) struct dtv_frontend_properties *fep = &fe->dtv_property_cache; struct dtt200u_fe_state *state = fe->demodulator_priv; u16 freq = fep->frequency / 250000; - u8 bwbuf[2] = { SET_BANDWIDTH, 0 },freqbuf[3] = { SET_RF_FREQ, 0, 0 }; + mutex_lock(&state->data_mutex); + state->data[0] = SET_BANDWIDTH; switch (fep->bandwidth_hz) { case 8000000: - bwbuf[1] = 8; + state->data[1] = 8; break; case 7000000: - bwbuf[1] = 7; + state->data[1] = 7; break; case 6000000: - bwbuf[1] = 6; + state->data[1] = 6; break; default: - return -EINVAL; + ret = -EINVAL; + goto ret; } - dvb_usb_generic_write(state->d,bwbuf,2); + dvb_usb_generic_write(state->d, state->data, 2); - freqbuf[1] = freq & 0xff; - freqbuf[2] = (freq >> 8) & 0xff; - dvb_usb_generic_write(state->d,freqbuf,3); + state->data[0] = SET_RF_FREQ; + state->data[1] = freq & 0xff; + state->data[2] = (freq >> 8) & 0xff; + dvb_usb_generic_write(state->d, state->data, 3); - return 0; +ret: + mutex_unlock(&state->data_mutex); + return ret; } static int dtt200u_fe_get_frontend(struct dvb_frontend* fe, @@ -160,6 +194,7 @@ struct dvb_frontend* dtt200u_fe_attach(struct dvb_usb_device *d) deb_info("attaching frontend dtt200u\n"); state->d = d; + mutex_init(&state->data_mutex); memcpy(&state->frontend.ops,&dtt200u_fe_ops,sizeof(struct dvb_frontend_ops)); state->frontend.demodulator_priv = state; -- 2.7.4