From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Date: Mon, 07 May 2018 12:51:46 +0000 Subject: Re: [PATCH v2] serial: sh-sci: Use spin_{try}lock_irqsave instead of open coding version Message-Id: <20180507125146.75crpaj2scav7mql@linutronix.de> List-Id: References: <20180504163041.28726-1-wagi@monom.org> In-Reply-To: <20180504163041.28726-1-wagi@monom.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Daniel Wagner Cc: linux-kernel@vger.kernel.org, Geert Uytterhoeven , linux-rt-users@vger.kernel.org, linux-serial@vger.kernel.org, linux-sh@vger.kernel.org, gregkh@linuxfoundation.org, Daniel Wagner On 2018-05-04 18:30:41 [+0200], Daniel Wagner wrote: > --- a/drivers/tty/serial/sh-sci.c > +++ b/drivers/tty/serial/sh-sci.c > @@ -2890,16 +2890,16 @@ static void serial_console_write(struct console *co, const char *s, > unsigned long flags; > int locked = 1; > > - local_irq_save(flags); > #if defined(SUPPORT_SYSRQ) > - if (port->sysrq) > + if (port->sysrq) { > locked = 0; > - else > + local_irq_save(flags); how is this helping? You should see a splat after a sysrq request. > + } else > #endif > if (oops_in_progress) > - locked = spin_trylock(&port->lock); > + locked = spin_trylock_irqsave(&port->lock, flags); > else > - spin_lock(&port->lock); > + spin_lock_irqsave(&port->lock, flags); > > /* first save SCSCR then disable interrupts, keep clock source */ > ctrl = serial_port_in(port, SCSCR); Sebastian From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-1024697-1525697512-2-14314446486451217745 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, MAILING_LIST_MULTI -1, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, LANGUAGES enda, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='de', MailFrom='org' X-Spam-charsets: plain='utf-8' 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; 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Mon, 7 May 2018 08:51:49 -0400 Date: Mon, 7 May 2018 14:51:46 +0200 From: Sebastian Andrzej Siewior To: Daniel Wagner Cc: linux-kernel@vger.kernel.org, Geert Uytterhoeven , linux-rt-users@vger.kernel.org, linux-serial@vger.kernel.org, linux-sh@vger.kernel.org, gregkh@linuxfoundation.org, Daniel Wagner Subject: Re: [PATCH v2] serial: sh-sci: Use spin_{try}lock_irqsave instead of open coding version Message-ID: <20180507125146.75crpaj2scav7mql@linutronix.de> References: <20180504163041.28726-1-wagi@monom.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180504163041.28726-1-wagi@monom.org> User-Agent: NeoMutt/20180323 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: On 2018-05-04 18:30:41 [+0200], Daniel Wagner wrote: > --- a/drivers/tty/serial/sh-sci.c > +++ b/drivers/tty/serial/sh-sci.c > @@ -2890,16 +2890,16 @@ static void serial_console_write(struct console *co, const char *s, > unsigned long flags; > int locked = 1; > > - local_irq_save(flags); > #if defined(SUPPORT_SYSRQ) > - if (port->sysrq) > + if (port->sysrq) { > locked = 0; > - else > + local_irq_save(flags); how is this helping? You should see a splat after a sysrq request. > + } else > #endif > if (oops_in_progress) > - locked = spin_trylock(&port->lock); > + locked = spin_trylock_irqsave(&port->lock, flags); > else > - spin_lock(&port->lock); > + spin_lock_irqsave(&port->lock, flags); > > /* first save SCSCR then disable interrupts, keep clock source */ > ctrl = serial_port_in(port, SCSCR); Sebastian