From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> To: Christoph Hellwig <hch@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>, linux-pci@vger.kernel.org, Alexander Duyck <alexanderduyck@fb.com>, oss-drivers@corigine.com, Paul Mackerras <paulus@samba.org>, Herbert Xu <herbert@gondor.apana.org.au>, Michael Ellerman <mpe@ellerman.id.au>, Rafa?? Mi??ecki <zajec5@gmail.com>, Jesse Brandeburg <jesse.brandeburg@intel.com>, Bjorn Helgaas <helgaas@kernel.org>, Ido Schimmel <idosch@nvidia.com>, Jakub Kicinski <kuba@kernel.org>, Yisen Zhuang <yisen.zhuang@huawei.com>, Vadym Kochan <vkochan@marvell.com>, Michael Buesch <m@bues.ch>, Jiri Pirko <jiri@nvidia.com>, Salil Mehta <salil.mehta@huawei.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Taras Chornyi <tchornyi@marvell.com>, Zhou Wang <wangzhou1@hisilicon.com>, linux-crypto@vger.kernel.org, kernel@pengutronix.de, netdev@vger.kernel.org, Simon Horman <simon.horman@corigine.com>, Oliver O'Halloran <oohall@gmail.com>, linuxppc-dev@lists.ozlabs.org, "David S. Miller" <davem@davemloft.net> Subject: Re: [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name Date: Thu, 12 Aug 2021 10:14:25 +0200 [thread overview] Message-ID: <20210812081425.7pjy4a25e2ehkr3x@pengutronix.de> (raw) In-Reply-To: <YRTIqGm5Dr8du7a7@infradead.org> [-- Attachment #1: Type: text/plain, Size: 2565 bytes --] On Thu, Aug 12, 2021 at 08:07:20AM +0100, Christoph Hellwig wrote: > On Wed, Aug 11, 2021 at 10:06:33AM +0200, Uwe Kleine-K??nig wrote: > > static inline const char *eeh_driver_name(struct pci_dev *pdev) > > { > > - return (pdev && pdev->driver) ? pdev->driver->name : "<null>"; > > + const char *drvstr = pdev ? dev_driver_string(&pdev->dev) : ""; > > + > > + if (*drvstr == '\0') > > + return "<null>"; > > + > > + return drvstr; > > This looks rather obsfucated due to the fact that dev_driver_string > never returns '\0', and due to the strange mix of a tenary operation > and the if on a related condition. dev_driver_string() might return "" (via dev_bus_name()). If that happens *drvstr == '\0' becomes true. Would the following be better?: const char *drvstr; if (pdev) return "<null>"; drvstr = dev_driver_string(&pdev->dev); if (!strcmp(drvstr, "")) return "<null>"; return drvstr; When I thought about this hunk I considered it ugly to have "<null>" in it twice. > > } > > > > #endif /* CONFIG_EEH */ > > diff --git a/drivers/bcma/host_pci.c b/drivers/bcma/host_pci.c > > index 69c10a7b7c61..dc2ffa686964 100644 > > --- a/drivers/bcma/host_pci.c > > +++ b/drivers/bcma/host_pci.c > > @@ -175,9 +175,10 @@ static int bcma_host_pci_probe(struct pci_dev *dev, > > if (err) > > goto err_kfree_bus; > > > > - name = dev_name(&dev->dev); > > - if (dev->driver && dev->driver->name) > > - name = dev->driver->name; > > + name = dev_driver_string(&dev->dev); > > + if (*name == '\0') > > + name = dev_name(&dev->dev); > > Where does this '\0' check come from? The original code is equivalent to if (dev->driver && dev->driver->name) name = dev->driver->name; else: name = dev_name(...); As dev_driver_string() implements something like: if (dev->driver && dev->driver->name) return dev->driver->name; else return ""; the change looks fine to me. (One could wonder if it's sensible to fall back to the device name if the driver has no nice name, but this isn't new with my change.) > > + name = dev_driver_string(&dev->dev); > > + if (*name == '\0') > > + name = dev_name(&dev->dev); > > + > > More of this weirdness. I admit it's not pretty. Would it help to use !strcmp(name, "") instead of *name == '\0'? Any other constructive suggestion? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de> To: Christoph Hellwig <hch@infradead.org> Cc: Alexander Duyck <alexanderduyck@fb.com>, oss-drivers@corigine.com, Paul Mackerras <paulus@samba.org>, Herbert Xu <herbert@gondor.apana.org.au>, Ido Schimmel <idosch@nvidia.com>, Rafa?? Mi??ecki <zajec5@gmail.com>, Jesse Brandeburg <jesse.brandeburg@intel.com>, Bjorn Helgaas <helgaas@kernel.org>, linux-pci@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>, Yisen Zhuang <yisen.zhuang@huawei.com>, Vadym Kochan <vkochan@marvell.com>, Michael Buesch <m@bues.ch>, Jiri Pirko <jiri@nvidia.com>, Salil Mehta <salil.mehta@huawei.com>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, Taras Chornyi <tchornyi@marvell.com>, Zhou Wang <wangzhou1@hisilicon.com>, linux-crypto@vger.kernel.org, kernel@pengutronix.de, netdev@vger.kernel.org, Simon Horman <simon.horman@corigine.com>, Oliver O'Halloran <oohall@gmail.com>, linuxppc-dev@lists.ozlabs.org, "David S. Miller" <davem@davemloft.net> Subject: Re: [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name Date: Thu, 12 Aug 2021 10:14:25 +0200 [thread overview] Message-ID: <20210812081425.7pjy4a25e2ehkr3x@pengutronix.de> (raw) In-Reply-To: <YRTIqGm5Dr8du7a7@infradead.org> [-- Attachment #1: Type: text/plain, Size: 2565 bytes --] On Thu, Aug 12, 2021 at 08:07:20AM +0100, Christoph Hellwig wrote: > On Wed, Aug 11, 2021 at 10:06:33AM +0200, Uwe Kleine-K??nig wrote: > > static inline const char *eeh_driver_name(struct pci_dev *pdev) > > { > > - return (pdev && pdev->driver) ? pdev->driver->name : "<null>"; > > + const char *drvstr = pdev ? dev_driver_string(&pdev->dev) : ""; > > + > > + if (*drvstr == '\0') > > + return "<null>"; > > + > > + return drvstr; > > This looks rather obsfucated due to the fact that dev_driver_string > never returns '\0', and due to the strange mix of a tenary operation > and the if on a related condition. dev_driver_string() might return "" (via dev_bus_name()). If that happens *drvstr == '\0' becomes true. Would the following be better?: const char *drvstr; if (pdev) return "<null>"; drvstr = dev_driver_string(&pdev->dev); if (!strcmp(drvstr, "")) return "<null>"; return drvstr; When I thought about this hunk I considered it ugly to have "<null>" in it twice. > > } > > > > #endif /* CONFIG_EEH */ > > diff --git a/drivers/bcma/host_pci.c b/drivers/bcma/host_pci.c > > index 69c10a7b7c61..dc2ffa686964 100644 > > --- a/drivers/bcma/host_pci.c > > +++ b/drivers/bcma/host_pci.c > > @@ -175,9 +175,10 @@ static int bcma_host_pci_probe(struct pci_dev *dev, > > if (err) > > goto err_kfree_bus; > > > > - name = dev_name(&dev->dev); > > - if (dev->driver && dev->driver->name) > > - name = dev->driver->name; > > + name = dev_driver_string(&dev->dev); > > + if (*name == '\0') > > + name = dev_name(&dev->dev); > > Where does this '\0' check come from? The original code is equivalent to if (dev->driver && dev->driver->name) name = dev->driver->name; else: name = dev_name(...); As dev_driver_string() implements something like: if (dev->driver && dev->driver->name) return dev->driver->name; else return ""; the change looks fine to me. (One could wonder if it's sensible to fall back to the device name if the driver has no nice name, but this isn't new with my change.) > > + name = dev_driver_string(&dev->dev); > > + if (*name == '\0') > > + name = dev_name(&dev->dev); > > + > > More of this weirdness. I admit it's not pretty. Would it help to use !strcmp(name, "") instead of *name == '\0'? Any other constructive suggestion? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2021-08-12 8:16 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-11 8:06 [PATCH v3 0/8] PCI: Drop duplicated tracking of a pci_dev's bound driver Uwe Kleine-König 2021-08-11 8:06 ` Uwe Kleine-König 2021-08-11 8:06 ` [PATCH v3 1/8] PCI: Simplify pci_device_remove() Uwe Kleine-König 2021-08-12 6:44 ` Christoph Hellwig 2021-08-11 8:06 ` [PATCH v3 2/8] PCI: Drop useless check from pci_device_probe() Uwe Kleine-König 2021-08-12 6:46 ` Christoph Hellwig 2021-08-11 8:06 ` [PATCH v3 3/8] xen/pci: Drop some checks that are always true Uwe Kleine-König 2021-08-11 9:51 ` Uwe Kleine-König 2021-08-12 6:50 ` Christoph Hellwig 2021-08-11 8:06 ` [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name Uwe Kleine-König 2021-08-11 8:06 ` Uwe Kleine-König 2021-08-12 7:07 ` Christoph Hellwig 2021-08-12 7:07 ` Christoph Hellwig 2021-08-12 8:14 ` Uwe Kleine-König [this message] 2021-08-12 8:14 ` Uwe Kleine-König 2021-08-14 8:38 ` Christoph Hellwig 2021-08-14 8:38 ` Christoph Hellwig 2021-08-11 8:06 ` [PATCH v3 5/8] scsi: message: fusion: Remove unused parameter of mpt_pci driver's probe() Uwe Kleine-König 2021-08-12 2:51 ` Martin K. Petersen 2021-08-12 7:10 ` Christoph Hellwig 2021-08-11 8:06 ` [PATCH v3 6/8] crypto: qat - simplify adf_enable_aer() Uwe Kleine-König 2021-08-11 11:56 ` Giovanni Cabiddu 2021-08-11 21:34 ` Uwe Kleine-König 2021-08-12 14:43 ` Giovanni Cabiddu 2021-08-13 8:15 ` Uwe Kleine-König 2021-08-11 8:06 ` [PATCH v3 7/8] PCI: Replace pci_dev::driver usage by pci_dev::dev.driver Uwe Kleine-König 2021-08-11 8:06 ` Uwe Kleine-König 2021-08-11 14:07 ` Boris Ostrovsky 2021-08-11 14:07 ` Boris Ostrovsky 2021-08-11 8:06 ` [PATCH v3 8/8] PCI: Drop duplicated tracking of a pci_dev's bound driver Uwe Kleine-König
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