From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bartlomiej Zolnierkiewicz Subject: Re: [PATCH 3/15] qd65xx: fix deadlock on error handling Date: Thu, 4 Oct 2007 00:41:39 +0200 Message-ID: <200710040041.40047.bzolnier@gmail.com> References: <200710012333.02643.bzolnier@gmail.com> <200710030015.44586.bzolnier@gmail.com> <4702C3D9.6040606@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from mu-out-0910.google.com ([209.85.134.190]:54001 "EHLO mu-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753000AbXJCWht (ORCPT ); Wed, 3 Oct 2007 18:37:49 -0400 Received: by mu-out-0910.google.com with SMTP id i10so7656641mue for ; Wed, 03 Oct 2007 15:37:47 -0700 (PDT) In-Reply-To: <4702C3D9.6040606@garzik.org> Content-Disposition: inline Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: Sergei Shtylyov , linux-ide@vger.kernel.org On Wednesday 03 October 2007, Jeff Garzik wrote: > Bartlomiej Zolnierkiewicz wrote: > > ACK everything else (that I snipped)... > > > @@ -303,6 +281,7 @@ static void qd6580_set_pio_mode(ide_driv > > > > static int __init qd_testreg(int port) > > { > > + static DEFINE_SPINLOCK(qd65xx_lock); > > unsigned long flags; > > u8 savereg, readreg; > > At this point, the lock is largely pointless, isn't it? > > Seems like you might as well use local_irq_save/restore. Yeah. [PATCH] qd65xx: remove pointless qd_{read,write}_reg() (take 2) These functions are atomic so locking is pointless (noticed by Sergei). v2: We can now just use local_irq_save/restore() in qd_testreg() (noticed by Jeff). Cc: Sergei Shtylyov Cc: Jeff Garzik Signed-off-by: Bartlomiej Zolnierkiewicz --- drivers/ide/legacy/qd65xx.c | 46 +++++++++++--------------------------------- 1 file changed, 12 insertions(+), 34 deletions(-) Index: b/drivers/ide/legacy/qd65xx.c =================================================================== --- a/drivers/ide/legacy/qd65xx.c +++ b/drivers/ide/legacy/qd65xx.c @@ -89,28 +89,6 @@ static int timings[4]={-1,-1,-1,-1}; /* stores current timing for each timer */ -static DEFINE_SPINLOCK(qd65xx_lock); - -static void qd_write_reg (u8 content, unsigned long reg) -{ - unsigned long flags; - - spin_lock_irqsave(&qd65xx_lock, flags); - outb(content,reg); - spin_unlock_irqrestore(&qd65xx_lock, flags); -} - -static u8 __init qd_read_reg (unsigned long reg) -{ - unsigned long flags; - u8 read; - - spin_lock_irqsave(&qd65xx_lock, flags); - read = inb(reg); - spin_unlock_irqrestore(&qd65xx_lock, flags); - return read; -} - /* * qd_select: * @@ -123,7 +101,7 @@ static void qd_select (ide_drive_t *driv (QD_TIMREG(drive) & 0x02); if (timings[index] != QD_TIMING(drive)) - qd_write_reg(timings[index] = QD_TIMING(drive), QD_TIMREG(drive)); + outb(timings[index] = QD_TIMING(drive), QD_TIMREG(drive)); } /* @@ -286,7 +264,7 @@ static void qd6580_set_pio_mode(ide_driv } if (!HWIF(drive)->channel && drive->media != ide_disk) { - qd_write_reg(0x5f, QD_CONTROL_PORT); + outb(0x5f, QD_CONTROL_PORT); printk(KERN_WARNING "%s: ATAPI: disabled read-ahead FIFO " "and post-write buffer on %s.\n", drive->name, HWIF(drive)->name); @@ -306,12 +284,12 @@ static int __init qd_testreg(int port) unsigned long flags; u8 savereg, readreg; - spin_lock_irqsave(&qd65xx_lock, flags); + local_irq_save(flags); savereg = inb_p(port); outb_p(QD_TESTVAL, port); /* safe value */ readreg = inb_p(port); outb(savereg, port); - spin_unlock_irqrestore(&qd65xx_lock, flags); + local_irq_restore(flags); if (savereg == QD_TESTVAL) { printk(KERN_ERR "Outch ! the probe for qd65xx isn't reliable !\n"); @@ -365,13 +343,13 @@ static void __exit qd_unsetup(ide_hwif_t if (set_pio_mode == (void *)qd6500_set_pio_mode) { // will do it for both - qd_write_reg(QD6500_DEF_DATA, QD_TIMREG(&hwif->drives[0])); + outb(QD6500_DEF_DATA, QD_TIMREG(&hwif->drives[0])); } else if (set_pio_mode == (void *)qd6580_set_pio_mode) { if (QD_CONTROL(hwif) & QD_CONTR_SEC_DISABLED) { - qd_write_reg(QD6580_DEF_DATA, QD_TIMREG(&hwif->drives[0])); - qd_write_reg(QD6580_DEF_DATA2, QD_TIMREG(&hwif->drives[1])); + outb(QD6580_DEF_DATA, QD_TIMREG(&hwif->drives[0])); + outb(QD6580_DEF_DATA2, QD_TIMREG(&hwif->drives[1])); } else { - qd_write_reg(hwif->channel ? QD6580_DEF_DATA2 : QD6580_DEF_DATA, QD_TIMREG(&hwif->drives[0])); + outb(hwif->channel ? QD6580_DEF_DATA2 : QD6580_DEF_DATA, QD_TIMREG(&hwif->drives[0])); } } else { printk(KERN_WARNING "Unknown qd65xx tuning fonction !\n"); @@ -394,7 +372,7 @@ static int __init qd_probe(int base) u8 config; u8 unit; - config = qd_read_reg(QD_CONFIG_PORT); + config = inb(QD_CONFIG_PORT); if (! ((config & QD_CONFIG_BASEPORT) >> 1 == (base == 0xb0)) ) return 1; @@ -438,7 +416,7 @@ static int __init qd_probe(int base) /* qd6580 found */ - control = qd_read_reg(QD_CONTROL_PORT); + control = inb(QD_CONTROL_PORT); printk(KERN_NOTICE "qd6580 at %#x\n", base); printk(KERN_DEBUG "qd6580: config=%#x, control=%#x, ID3=%u\n", @@ -459,7 +437,7 @@ static int __init qd_probe(int base) ide_device_add(idx); - qd_write_reg(QD_DEF_CONTR, QD_CONTROL_PORT); + outb(QD_DEF_CONTR, QD_CONTROL_PORT); return 1; } else { @@ -486,7 +464,7 @@ static int __init qd_probe(int base) ide_device_add(idx); - qd_write_reg(QD_DEF_CONTR, QD_CONTROL_PORT); + outb(QD_DEF_CONTR, QD_CONTROL_PORT); return 0; /* no other qd65xx possible */ }