| Message ID | 201110111913.18492.bzolnier@gmail.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Date: Tue, 11 Oct 2011 19:13:18 +0200 > From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> > Subject: [PATCH] ide: ide_port_wait_ready() fix > > Fix for commit a20b2a4 ("ide: skip probe if there are no devices on > the port (v2)"). We must check for slave device before failing. > > Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> This will mishandle the case where there is no slave in the device list. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
David Miller wrote: > From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> > Date: Tue, 11 Oct 2011 19:13:18 +0200 > > > From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> > > Subject: [PATCH] ide: ide_port_wait_ready() fix > > > > Fix for commit a20b2a4 ("ide: skip probe if there are no devices on > > the port (v2)"). We must check for slave device before failing. > > > > Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> > > This will mishandle the case where there is no slave in the device > list. I don't see it: @ -598,7 +598,7 @@ static int ide_port_wait_ready(ide_hwif_ { const struct ide_tp_ops *tp_ops = hwif->tp_ops; ide_drive_t *drive; - int i, rc; + int i, rc, prev_rc = 0; printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name); @@ -623,8 +623,10 @@ static int ide_port_wait_ready(ide_hwif_ tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS); mdelay(2); rc = ide_wait_not_busy(hwif, 35000); - if (rc) + if (prev_rc && rc) goto out; + prev_rc = rc; + rc = 0; } else printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped\n", drive->name); If there is no slave device but there is a master device the code falls-through and returns a success. The patch fixes regression introduced in commit a20b2a4 as some esoteric setups return ide_wait_not_busy() -ENODEV error on master device while there is slave device present in the system. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Date: Wed, 12 Oct 2011 16:59:55 +0200 > David Miller wrote: > >> From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> >> Date: Tue, 11 Oct 2011 19:13:18 +0200 >> >> > From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> >> > Subject: [PATCH] ide: ide_port_wait_ready() fix >> > >> > Fix for commit a20b2a4 ("ide: skip probe if there are no devices on >> > the port (v2)"). We must check for slave device before failing. >> > >> > Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> >> >> This will mishandle the case where there is no slave in the device >> list. > > I don't see it: > > @ -598,7 +598,7 @@ static int ide_port_wait_ready(ide_hwif_ > { > const struct ide_tp_ops *tp_ops = hwif->tp_ops; > ide_drive_t *drive; > - int i, rc; > + int i, rc, prev_rc = 0; > > printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name); > > @@ -623,8 +623,10 @@ static int ide_port_wait_ready(ide_hwif_ > tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS); > mdelay(2); > rc = ide_wait_not_busy(hwif, 35000); > - if (rc) > + if (prev_rc && rc) > goto out; > + prev_rc = rc; > + rc = 0; > } else > printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped\n", > drive->name); > > If there is no slave device but there is a master device the code falls-through > and returns a success. That's not what we want, if there is only a master device and no slave device in the list this loop is iterating over we want to return the error code in "rc", not zero. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
David Miller wrote: > From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> > Date: Wed, 12 Oct 2011 16:59:55 +0200 > > > David Miller wrote: > > > >> From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> > >> Date: Tue, 11 Oct 2011 19:13:18 +0200 > >> > >> > From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> > >> > Subject: [PATCH] ide: ide_port_wait_ready() fix > >> > > >> > Fix for commit a20b2a4 ("ide: skip probe if there are no devices on > >> > the port (v2)"). We must check for slave device before failing. > >> > > >> > Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> > >> > >> This will mishandle the case where there is no slave in the device > >> list. > > > > I don't see it: > > > > @ -598,7 +598,7 @@ static int ide_port_wait_ready(ide_hwif_ > > { > > const struct ide_tp_ops *tp_ops = hwif->tp_ops; > > ide_drive_t *drive; > > - int i, rc; > > + int i, rc, prev_rc = 0; > > > > printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name); > > > > @@ -623,8 +623,10 @@ static int ide_port_wait_ready(ide_hwif_ > > tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS); > > mdelay(2); > > rc = ide_wait_not_busy(hwif, 35000); > > - if (rc) > > + if (prev_rc && rc) > > goto out; > > + prev_rc = rc; > > + rc = 0; > > } else > > printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped\n", > > drive->name); > > > > If there is no slave device but there is a master device the code falls-through > > and returns a success. > > That's not what we want, if there is only a master device and no slave device > in the list this loop is iterating over we want to return the error code > in "rc", not zero. No, we want to return zero (success) since at least once device was found (otherwise we fail probe on some esoteric setups returning -ENODEV from ide_wait_not_busy() for master device). This is how this function worked before commit a20b2a4 if you want something else okay but it needs to work with aforementioned setups. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Date: Thu, 13 Oct 2011 12:41:04 +0200 > David Miller wrote: > >> From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> >> Date: Wed, 12 Oct 2011 16:59:55 +0200 >> >> > David Miller wrote: >> > >> >> From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> >> >> Date: Tue, 11 Oct 2011 19:13:18 +0200 >> >> >> >> > From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> >> >> > Subject: [PATCH] ide: ide_port_wait_ready() fix >> >> > >> >> > Fix for commit a20b2a4 ("ide: skip probe if there are no devices on >> >> > the port (v2)"). We must check for slave device before failing. >> >> > >> >> > Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> >> >> >> >> This will mishandle the case where there is no slave in the device >> >> list. >> > >> > I don't see it: >> > >> > @ -598,7 +598,7 @@ static int ide_port_wait_ready(ide_hwif_ >> > { >> > const struct ide_tp_ops *tp_ops = hwif->tp_ops; >> > ide_drive_t *drive; >> > - int i, rc; >> > + int i, rc, prev_rc = 0; >> > >> > printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name); >> > >> > @@ -623,8 +623,10 @@ static int ide_port_wait_ready(ide_hwif_ >> > tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS); >> > mdelay(2); >> > rc = ide_wait_not_busy(hwif, 35000); >> > - if (rc) >> > + if (prev_rc && rc) >> > goto out; >> > + prev_rc = rc; >> > + rc = 0; >> > } else >> > printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped\n", >> > drive->name); >> > >> > If there is no slave device but there is a master device the code falls-through >> > and returns a success. >> >> That's not what we want, if there is only a master device and no slave device >> in the list this loop is iterating over we want to return the error code >> in "rc", not zero. > > No, we want to return zero (success) since at least once device was found > (otherwise we fail probe on some esoteric setups returning -ENODEV from > ide_wait_not_busy() for master device). > > This is how this function worked before commit a20b2a4 if you want something > else okay but it needs to work with aforementioned setups. You unconditionally assign "prev_rc = rc" and set "rc = 0" so if we only run the loop once, we return zero. And we do this even if that one device gave a non-zero return value. That's not what we want. -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: b/drivers/ide/ide-probe.c =================================================================== --- a/drivers/ide/ide-probe.c +++ b/drivers/ide/ide-probe.c @@ -598,7 +598,7 @@ static int ide_port_wait_ready(ide_hwif_ { const struct ide_tp_ops *tp_ops = hwif->tp_ops; ide_drive_t *drive; - int i, rc; + int i, rc, prev_rc = 0; printk(KERN_DEBUG "Probing IDE interface %s...\n", hwif->name); @@ -623,8 +623,10 @@ static int ide_port_wait_ready(ide_hwif_ tp_ops->write_devctl(hwif, ATA_DEVCTL_OBS); mdelay(2); rc = ide_wait_not_busy(hwif, 35000); - if (rc) + if (prev_rc && rc) goto out; + prev_rc = rc; + rc = 0; } else printk(KERN_DEBUG "%s: ide_wait_not_busy() skipped\n", drive->name);