Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753766AbcJKKSC (ORCPT ); Tue, 11 Oct 2016 06:18:02 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:56776 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752684AbcJKKLj (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 05/31] cinergyT2-fe: don't do DMA on stack Date: Tue, 11 Oct 2016 07:09:20 -0300 Message-Id: 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: 3898 Lines: 128 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. Reviewed-By: Patrick Boettcher Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/dvb-usb/cinergyT2-fe.c | 56 +++++++++++++++++++------------- 1 file changed, 33 insertions(+), 23 deletions(-) diff --git a/drivers/media/usb/dvb-usb/cinergyT2-fe.c b/drivers/media/usb/dvb-usb/cinergyT2-fe.c index fd8edcb56e61..2d29b4174dba 100644 --- a/drivers/media/usb/dvb-usb/cinergyT2-fe.c +++ b/drivers/media/usb/dvb-usb/cinergyT2-fe.c @@ -139,6 +139,10 @@ static uint16_t compute_tps(struct dtv_frontend_properties *op) struct cinergyt2_fe_state { struct dvb_frontend fe; struct dvb_usb_device *d; + + unsigned char data[64]; + struct mutex data_mutex; + struct dvbt_get_status_msg status; }; @@ -146,28 +150,31 @@ static int cinergyt2_fe_read_status(struct dvb_frontend *fe, enum fe_status *status) { struct cinergyt2_fe_state *state = fe->demodulator_priv; - struct dvbt_get_status_msg result; - u8 cmd[] = { CINERGYT2_EP1_GET_TUNER_STATUS }; int ret; - ret = dvb_usb_generic_rw(state->d, cmd, sizeof(cmd), (u8 *)&result, - sizeof(result), 0); + mutex_lock(&state->data_mutex); + state->data[0] = CINERGYT2_EP1_GET_TUNER_STATUS; + + ret = dvb_usb_generic_rw(state->d, state->data, 1, + state->data, sizeof(state->status), 0); + if (!ret) + memcpy(&state->status, state->data, sizeof(state->status)); + mutex_unlock(&state->data_mutex); + if (ret < 0) return ret; - state->status = result; - *status = 0; - if (0xffff - le16_to_cpu(result.gain) > 30) + if (0xffff - le16_to_cpu(state->status.gain) > 30) *status |= FE_HAS_SIGNAL; - if (result.lock_bits & (1 << 6)) + if (state->status.lock_bits & (1 << 6)) *status |= FE_HAS_LOCK; - if (result.lock_bits & (1 << 5)) + if (state->status.lock_bits & (1 << 5)) *status |= FE_HAS_SYNC; - if (result.lock_bits & (1 << 4)) + if (state->status.lock_bits & (1 << 4)) *status |= FE_HAS_CARRIER; - if (result.lock_bits & (1 << 1)) + if (state->status.lock_bits & (1 << 1)) *status |= FE_HAS_VITERBI; if ((*status & (FE_HAS_CARRIER | FE_HAS_VITERBI | FE_HAS_SYNC)) != @@ -232,34 +239,36 @@ static int cinergyt2_fe_set_frontend(struct dvb_frontend *fe) { struct dtv_frontend_properties *fep = &fe->dtv_property_cache; struct cinergyt2_fe_state *state = fe->demodulator_priv; - struct dvbt_set_parameters_msg param; - char result[2]; + struct dvbt_set_parameters_msg *param; int err; - param.cmd = CINERGYT2_EP1_SET_TUNER_PARAMETERS; - param.tps = cpu_to_le16(compute_tps(fep)); - param.freq = cpu_to_le32(fep->frequency / 1000); - param.flags = 0; + mutex_lock(&state->data_mutex); + + param = (void *)state->data; + param->cmd = CINERGYT2_EP1_SET_TUNER_PARAMETERS; + param->tps = cpu_to_le16(compute_tps(fep)); + param->freq = cpu_to_le32(fep->frequency / 1000); + param->flags = 0; switch (fep->bandwidth_hz) { default: case 8000000: - param.bandwidth = 8; + param->bandwidth = 8; break; case 7000000: - param.bandwidth = 7; + param->bandwidth = 7; break; case 6000000: - param.bandwidth = 6; + param->bandwidth = 6; break; } - err = dvb_usb_generic_rw(state->d, - (char *)¶m, sizeof(param), - result, sizeof(result), 0); + err = dvb_usb_generic_rw(state->d, state->data, sizeof(*param), + state->data, 2, 0); if (err < 0) err("cinergyt2_fe_set_frontend() Failed! err=%d\n", err); + mutex_unlock(&state->data_mutex); return (err < 0) ? err : 0; } @@ -281,6 +290,7 @@ struct dvb_frontend *cinergyt2_fe_attach(struct dvb_usb_device *d) s->d = d; memcpy(&s->fe.ops, &cinergyt2_fe_ops, sizeof(struct dvb_frontend_ops)); s->fe.demodulator_priv = s; + mutex_init(&s->data_mutex); return &s->fe; } -- 2.7.4