Subject: + drivers-pci-pci-driverc-warn-on-driver-probe-return-value-greater-than-zero.patch added to -mm tree
To: scameron@xxxxxxxxxxxxxxxxxx,axboe@xxxxxxxxx,bhelgaas@xxxxxxxxxx,greg@xxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Fri, 01 Nov 2013 12:46:26 -0700
The patch titled
Subject: drivers/pci/pci-driver.c: warn on driver probe return value greater than zero
has been added to the -mm tree. Its filename is
drivers-pci-pci-driverc-warn-on-driver-probe-return-value-greater-than-zero.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/drivers-pci-pci-driverc-warn-on-driver-probe-return-value-greater-than-zero.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/drivers-pci-pci-driverc-warn-on-driver-probe-return-value-greater-than-zero.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Stephen M. Cameron <scameron@xxxxxxxxxxxxxxxxxx>
Subject: drivers/pci/pci-driver.c: warn on driver probe return value greater than zero
Ages ago, drivers could return values greater than zero from their probe
function and this would be regarded as success. Commit f3ec4f87d607f40497
"PCI: change device runtime PM settings for probe and remove" slightly
altered this in 2010, and commit 967577b062417b4e4b8e27b ("PCI/PM: Keep
runtime PM enabled for unbound PCI devices") in late 2012 altered it more
signficantly, setting pci_dev->driver to NULL if the driver's probe
function returned a value greater than zero, which would for example
prevent the driver's remove function from being called on rmmod.
Neither of those changes would necessarily make the driver fail in an
obvious way though, and so at least a couple drivers (cciss, hpsa) fell
into this hole since they were returning 1, and this situation went
unnoticed for quite some time.
If a driver's probe function returns a value greater than zero, issue a
warning, but otherwise treat this as success.
Signed-off-by: Stephen M. Cameron <scameron@xxxxxxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Greg KH <greg@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/pci/pci-driver.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff -puN drivers/pci/pci-driver.c~drivers-pci-pci-driverc-warn-on-driver-probe-return-value-greater-than-zero drivers/pci/pci-driver.c
--- a/drivers/pci/pci-driver.c~drivers-pci-pci-driverc-warn-on-driver-probe-return-value-greater-than-zero
+++ a/drivers/pci/pci-driver.c
@@ -264,11 +264,19 @@ static long local_pci_probe(void *_ddi)
pm_runtime_get_sync(dev);
pci_dev->driver = pci_drv;
rc = pci_drv->probe(pci_dev, ddi->id);
- if (rc) {
+ if (!rc)
+ return rc;
+ if (rc < 0) {
pci_dev->driver = NULL;
pm_runtime_put_sync(dev);
+ return rc;
}
- return rc;
+ /*
+ * Probe function should return < 0 for failure, 0 for success
+ * Treat values > 0 as success, but warn.
+ */
+ dev_warn(dev, "Driver probe function unexpectedly returned %d\n", rc);
+ return 0;
}
static int pci_call_probe(struct pci_driver *drv, struct pci_dev *dev,
_
Patches currently in -mm which might be from scameron@xxxxxxxxxxxxxxxxxx are
drivers-pci-pci-driverc-warn-on-driver-probe-return-value-greater-than-zero.patch
hpsa-return-0-from-driver-probe-function-on-success-not-1.patch
drivers-block-ccissc-return-0-from-driver-probe-function-on-success-not-1.patch
drivers-block-ccissc-cciss_init_one-use-proper-errnos.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
