From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47302 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750742AbdCNJOG (ORCPT ); Tue, 14 Mar 2017 05:14:06 -0400 Subject: patch "usb: musb: cppi41: don't check early-TX-interrupt for Isoch transfer" added to usb-linus To: b-liu@ti.com, abailon@baylibre.com, bigeasy@linutronix.de, gregkh@linuxfoundation.org, stable@vger.kernel.org From: Date: Tue, 14 Mar 2017 17:13:52 +0800 Message-ID: <1489482832125124@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled usb: musb: cppi41: don't check early-TX-interrupt for Isoch transfer to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >>From 0090114d336a9604aa2d90bc83f20f7cd121b76c Mon Sep 17 00:00:00 2001 From: Bin Liu Date: Fri, 10 Mar 2017 14:43:35 -0600 Subject: usb: musb: cppi41: don't check early-TX-interrupt for Isoch transfer The CPPI 4.1 driver polls register to workaround the premature TX interrupt issue, but it causes audio playback underrun when triggered in Isoch transfers. Isoch doesn't do back-to-back transfers, the TX should be done by the time the next transfer is scheduled. So skip this polling workaround for Isoch transfer. Fixes: a655f481d83d6 ("usb: musb: musb_cppi41: handle pre-mature TX complete interrupt") Cc: #4.1+ Reported-by: Alexandre Bailon Acked-by: Sebastian Andrzej Siewior Tested-by: Alexandre Bailon Signed-off-by: Bin Liu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/musb/musb_cppi41.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c index 00e272bfee39..355655f8a3fb 100644 --- a/drivers/usb/musb/musb_cppi41.c +++ b/drivers/usb/musb/musb_cppi41.c @@ -238,8 +238,27 @@ static void cppi41_dma_callback(void *private_data, transferred < cppi41_channel->packet_sz) cppi41_channel->prog_len = 0; - if (cppi41_channel->is_tx) - empty = musb_is_tx_fifo_empty(hw_ep); + if (cppi41_channel->is_tx) { + u8 type; + + if (is_host_active(musb)) + type = hw_ep->out_qh->type; + else + type = hw_ep->ep_in.type; + + if (type == USB_ENDPOINT_XFER_ISOC) + /* + * Don't use the early-TX-interrupt workaround below + * for Isoch transfter. Since Isoch are periodic + * transfer, by the time the next transfer is + * scheduled, the current one should be done already. + * + * This avoids audio playback underrun issue. + */ + empty = true; + else + empty = musb_is_tx_fifo_empty(hw_ep); + } if (!cppi41_channel->is_tx || empty) { cppi41_trans_done(cppi41_channel); -- 2.12.0