From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-2609372-1518094572-2-2584026440995333287 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no ("Email failed DMARC policy for domain") X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org' X-Spam-charsets: X-IgnoreVacation: yes ("Email failed DMARC policy for domain") X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-serial-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1518094572; b=gmyhYGHeeLBC1mMSP/g+VKmHFEffaslBbkxxFw11KyTvhm3 bI5EuKSLFXahSJddQNDc5LT/ZOszBnh/6HsaLfCTmWqVRW4GwUEpZ/8ppHAyokEe nKeM2mnfmlaEG9PEoE4xj8iulE9U4AcpK0wgxAFY5PB0QcE/+otBiCnQQ8pdawg9 8j884nkt9/Kz1jYYOZKN+CHxzOswN7qnVPnHJXrA2ZRf81vvMzIXbIRXtX9WYEca 3GSSBZKAL1PXYu3JDY2YTkvHVOhEqdach8Gt/1wOmDLgfcW44VRuMo7hcc6HVOrF NPys9IJ09bYX0h45gA4hGJ7HNt1aWOSXsao0Auw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1518094572; bh=v6dw1tNTSdrRFYg2AW8exP7/7U akjbYzktVqwU0+0kY=; b=kL8twb9IR/Tef+yUSSqeOqNhgkfsHBqVJtEovHkUrP F6JCfdc1sxSle8gsCfdr69PBQDOGW/MHaeiLehjtESHmVRp89xzDgLSFyzkU/pMd Zm61BH7gJOzemweTnc0/CarcQ5f6ndpqkFvNmVpS1PXZ45giTXHI1YkqWFTJxfqp beMK1d75uHR94dUIl0xd7KUbfmTwUxbV6/GtWBd5GlaPmGnJxeibJHue8hJ+H2L1 E2PkH/plunQpCCT0Ts64qpN6bVe8YyDs/GWhF5Gn11dO1Q+2HDdPbgexVa2o4lx3 4Gf1FCuz/BbHwP7tDvOLvVsXYwreR6qNRXyt2Fw8Fqrw== ARC-Authentication-Results: i=1; mx3.messagingengine.com; arc=none (no signatures found); dkim=fail (body has been altered; 1024-bit rsa key sha256) header.d=ti.com header.i=@ti.com header.b=UmziayKj x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=ti-com-17Q1; dmarc=fail (p=quarantine,has-list-id=yes,d=quarantine) header.from=ti.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-serial-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=ti.com header.result=pass header_is_org_domain=yes Authentication-Results: mx3.messagingengine.com; arc=none (no signatures found); dkim=fail (body has been altered; 1024-bit rsa key sha256) header.d=ti.com header.i=@ti.com header.b=UmziayKj x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=ti-com-17Q1; dmarc=fail (p=quarantine,has-list-id=yes,d=quarantine) header.from=ti.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-serial-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=ti.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751878AbeBHMz4 (ORCPT ); Thu, 8 Feb 2018 07:55:56 -0500 Received: from lelnx193.ext.ti.com ([198.47.27.77]:38770 "EHLO lelnx193.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751963AbeBHMzc (ORCPT ); Thu, 8 Feb 2018 07:55:32 -0500 From: Vignesh R To: Greg Kroah-Hartman CC: Jiri Slaby , Andy Shevchenko , , , , , Vignesh R Subject: [PATCH 1/2] serial: 8250: Don't service RX FIFO if interrupts are disabled Date: Thu, 8 Feb 2018 18:25:41 +0530 Message-ID: <20180208125542.15649-2-vigneshr@ti.com> X-Mailer: git-send-email 2.16.1 In-Reply-To: <20180208125542.15649-1-vigneshr@ti.com> References: <20180208125542.15649-1-vigneshr@ti.com> MIME-Version: 1.0 Content-Type: text/plain X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-serial-owner@vger.kernel.org X-Mailing-List: linux-serial@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Currently, data in RX FIFO is read based on UART_LSR register state even if RDI and RLSI interrupts are disabled in UART_IER register. This is because when IRQ handler is called due to TX FIFO empty event, RX FIFO is serviced based on UART_LSR register status instead of UART_IIR status. This defeats the purpose of disabling UART RX FIFO interrupts during throttling(see, omap_8250_throttle()) as IRQ handler continues to drain UART RX FIFO resulting in overflow of buffer at tty layer. Fix this by making sure that driver drains UART RX FIFO only when UART_IIR_RDI is set along with UART_LSR_BI or UART_LSR_DR bits. Signed-off-by: Vignesh R --- drivers/tty/serial/8250/8250_port.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 1328c7e70108..ffbb955d1c06 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1854,7 +1854,8 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) status = serial_port_in(port, UART_LSR); - if (status & (UART_LSR_DR | UART_LSR_BI)) { + if (status & (UART_LSR_DR | UART_LSR_BI) && + iir & UART_IIR_RDI) { if (!up->dma || handle_rx_dma(up, iir)) status = serial8250_rx_chars(up, status); } -- 2.16.1