From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 1/8] tty: serial: fsl_lpuart: consider TX FIFO too in tx_empty To: Greg KH References: <20160609151039.20817-1-bhuvanchandra.dv@toradex.com> <20160609151039.20817-2-bhuvanchandra.dv@toradex.com> <20160625212600.GA28726@kroah.com> CC: , , , , , , , , , From: Bhuvanchandra DV Message-ID: Date: Tue, 28 Jun 2016 09:24:00 +0530 MIME-Version: 1.0 In-Reply-To: <20160625212600.GA28726@kroah.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Return-Path: bhuvanchandra.dv@toradex.com List-ID: On 06/26/16 02:56, Greg KH wrote: > On Thu, Jun 09, 2016 at 08:40:32PM +0530, Bhuvanchandra DV wrote: >> From: Stefan Agner >> >> Currently the tx_empty callback only considers the Transmit Complete >> Flag (TC). The reference manual is not quite clear if the TC flag >> covers the TX FIFO too. Debug prints on real hardware have shown that >> from time to time the TC flag is asserted (indicating Transmitter >> idle) while there are still data in the TX FIFO. Hence, in this case >> the serial core will call the shutdown callback even though there are >> data remaining in the TX FIFO buffers. >> >> Avoid early shutdowns by considering the TX FIFO empty flag too. Also >> avoid theoretical race conditions between DMA and the driver by >> checking whether the TX DMA is in progress too. >> >> Signed-off-by: Stefan Agner >> --- >> drivers/tty/serial/fsl_lpuart.c | 14 ++++++++++++-- >> 1 file changed, 12 insertions(+), 2 deletions(-) > Why are you not signing off on patches that are flowing through you? > Please fix this up and resend the series, after breaking up the clock > change as asked. Okay > > thanks, > > greg k-h