From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Hurley Subject: Re: [PATCH LINUX v3 00/10] tty: xuartps: Fix lock ups Date: Sat, 5 Dec 2015 12:49:07 -0500 Message-ID: <56632393.8090809@hurleysoftware.com> References: <1448161172-19717-1-git-send-email-soren.brinkmann@xilinx.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1448161172-19717-1-git-send-email-soren.brinkmann@xilinx.com> Sender: linux-kernel-owner@vger.kernel.org To: Soren Brinkmann , Greg Kroah-Hartman Cc: Jiri Slaby , Michal Simek , linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-serial@vger.kernel.org On 11/21/2015 09:59 PM, Soren Brinkmann wrote: > Hi, >=20 > here is v3 of this series. It's largely the same as before, but I > adjusted 'tty: xuartps: Don't consider circular buffer when enabling > transmitter' according to Peter's suggestions. In reviewing this series, I thought the _OFFSET suffix for every regist= er address to be excessive. I would refactor all that out; IOW, - isrstatus =3D readl(port->membase + CDNS_UART_ISR_OFFSET); + isrstatus =3D readl(port->membase + CDNS_UART_ISR); > I also spent some time trying to get Peter's test for flow control an= d > xchar running. The xchar thing fails and will need some more work, bu= t I > think in general it should be possible to get it to work. > The flow control test passes: >=20 > root@Xilinx-ZC1751-DC1:~# ./flow /dev/ttyPS0 > Test flow control on /dev/ttyPS0 > begin test1 > patterns sent: 223 recvd: 208 > read distribution: 1 =3D 0 > 2+ =3D 0 > 4+ =3D 0 > 8+ =3D 0 > 16+ =3D 0 > 32+ =3D 643 > 64+ =3D 0 > 128+ =3D 0 > 256+ =3D 0 > 512+ =3D 0 > PASSED This distribution looks like this exactly because the xchar test is failing. IOW, this driver isn't performing soft flow control (^S,^Q) like it should. Regards, Peter Hurley > root@Xilinx-ZC1751-DC1:~# ./flow /dev/ttyPS1 > Test flow control on /dev/ttyPS1 > begin test1 > patterns sent: 223 recvd: 208 > read distribution: 1 =3D 0 > 2+ =3D 0 > 4+ =3D 0 > 8+ =3D 0 > 16+ =3D 0 > 32+ =3D 643 > 64+ =3D 0 > 128+ =3D 0 > 256+ =3D 0 > 512+ =3D 0 > PASSED >=20 > S=C3=B6ren >=20 > S=C3=B6ren Brinkmann (10): > tty: xuartps: Beautify read-modify writes > tty: xuartps: Use spinlock to serialize HW access > tty: xuartps: Don't consider circular buffer when enabling transmit= ter > tty: xuartps: Clear interrupt status register in shutdown > tty: xuartps: Improve startup function > tty: xuartps: Keep lock for whole ISR > tty: xuartps: Acquire port lock for shutdown > tty: xuartps: Move RX path into helper function > tty: xuartps: Only handle RX IRQs when RX is enabled > tty: xuartps: Cleanup: Reformat if-else >=20 > drivers/tty/serial/xilinx_uartps.c | 246 +++++++++++++++++++++------= ---------- > 1 file changed, 137 insertions(+), 109 deletions(-) >=20