From: Sinan Kaya <okaya@codeaurora.org> To: Bjorn Helgaas <helgaas@kernel.org> Cc: linux-pci@vger.kernel.org, timur@codeaurora.org, alex.williamson@redhat.com, linux-arm-msm@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/5] PCI: handle FLR failure and allow other reset types Date: Thu, 12 Oct 2017 12:42:08 -0400 [thread overview] Message-ID: <972aee6d-7f55-12f5-08ef-7809b7f133e0@codeaurora.org> (raw) In-Reply-To: <20171011210057.GU25517@bhelgaas-glaptop.roam.corp.google.com> On 10/11/2017 5:00 PM, Bjorn Helgaas wrote: > On Sat, Sep 23, 2017 at 08:16:55PM -0400, Sinan Kaya wrote: >> pci_flr_wait() and pci_af_flr() functions assume graceful return even >> though the device is inaccessible under error conditions. >> >> Return -ENOTTY in error cases so that __pci_reset_function_locked() can >> try other reset types if AF_FLR/FLR reset fails. > > This makes sense to me, but I think the error handling in > __pci_reset_function_locked() is confusing. It currently is: > > rc = pci_dev_specific_reset(dev, 0); > if (rc != -ENOTTY) > return rc; > if (pcie_has_flr(dev)) { > pcie_flr(dev); > return 0; > } > rc = pci_af_flr(dev, 0); > if (rc != -ENOTTY) > return rc; > > Would it make sense to change this to the following? > > rc = pci_dev_specific_reset(dev, 0); > if (rc == 0) > return 0; > > if (pcie_has_flr(dev)) { > pcie_flr(dev); > return 0; > } > > rc = pci_af_flr(dev, 0); > if (rc == 0) > return 0; > Yeah, this is cleaner. I'll create a separate patch for that. > I found two cases where this would make a difference: reset_ivb_igd() > returns -ENOMEM if pci_iomap() fails, and pci_pm_reset() returns > -EINVAL if the device is not in D0. > > In both cases we currently return the failure, but it would seem > reasonable to me to try another reset method. > > That could be done in a new patch before this one. Then *this* patch > could use -ETIMEDOUT instead of -ENOTTY, and I think the whole thing > would become a little more readable. > >> Signed-off-by: Sinan Kaya <okaya@codeaurora.org> >> --- -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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From: okaya@codeaurora.org (Sinan Kaya) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 2/5] PCI: handle FLR failure and allow other reset types Date: Thu, 12 Oct 2017 12:42:08 -0400 [thread overview] Message-ID: <972aee6d-7f55-12f5-08ef-7809b7f133e0@codeaurora.org> (raw) In-Reply-To: <20171011210057.GU25517@bhelgaas-glaptop.roam.corp.google.com> On 10/11/2017 5:00 PM, Bjorn Helgaas wrote: > On Sat, Sep 23, 2017 at 08:16:55PM -0400, Sinan Kaya wrote: >> pci_flr_wait() and pci_af_flr() functions assume graceful return even >> though the device is inaccessible under error conditions. >> >> Return -ENOTTY in error cases so that __pci_reset_function_locked() can >> try other reset types if AF_FLR/FLR reset fails. > > This makes sense to me, but I think the error handling in > __pci_reset_function_locked() is confusing. It currently is: > > rc = pci_dev_specific_reset(dev, 0); > if (rc != -ENOTTY) > return rc; > if (pcie_has_flr(dev)) { > pcie_flr(dev); > return 0; > } > rc = pci_af_flr(dev, 0); > if (rc != -ENOTTY) > return rc; > > Would it make sense to change this to the following? > > rc = pci_dev_specific_reset(dev, 0); > if (rc == 0) > return 0; > > if (pcie_has_flr(dev)) { > pcie_flr(dev); > return 0; > } > > rc = pci_af_flr(dev, 0); > if (rc == 0) > return 0; > Yeah, this is cleaner. I'll create a separate patch for that. > I found two cases where this would make a difference: reset_ivb_igd() > returns -ENOMEM if pci_iomap() fails, and pci_pm_reset() returns > -EINVAL if the device is not in D0. > > In both cases we currently return the failure, but it would seem > reasonable to me to try another reset method. > > That could be done in a new patch before this one. Then *this* patch > could use -ETIMEDOUT instead of -ENOTTY, and I think the whole thing > would become a little more readable. > >> Signed-off-by: Sinan Kaya <okaya@codeaurora.org> >> --- -- Sinan Kaya Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
next prev parent reply other threads:[~2017-10-12 16:42 UTC|newest] Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-09-24 0:16 [PATCH 1/5] PCI: protect restore with device lock to be consistent Sinan Kaya 2017-09-24 0:16 ` Sinan Kaya 2017-09-24 0:16 ` Sinan Kaya 2017-09-24 0:16 ` [PATCH 2/5] PCI: handle FLR failure and allow other reset types Sinan Kaya 2017-09-24 0:16 ` Sinan Kaya 2017-09-24 0:16 ` Sinan Kaya 2017-10-11 21:00 ` Bjorn Helgaas 2017-10-11 21:00 ` Bjorn Helgaas 2017-10-11 21:00 ` Bjorn Helgaas 2017-10-12 16:42 ` Sinan Kaya [this message] 2017-10-12 16:42 ` Sinan Kaya 2017-09-24 0:16 ` [PATCH 3/5] PCI: make pci_flr_wait() generic and rename to pci_dev_wait() Sinan Kaya 2017-09-24 0:16 ` Sinan Kaya 2017-09-24 13:08 ` Christoph Hellwig 2017-09-24 13:08 ` Christoph Hellwig 2017-09-24 13:08 ` Christoph Hellwig 2017-09-25 0:30 ` Sinan Kaya 2017-09-25 0:30 ` Sinan Kaya 2017-09-25 0:30 ` Sinan Kaya 2017-09-24 0:16 ` [PATCH 4/5] PCI: wait device ready after pci_pm_reset() Sinan Kaya 2017-09-24 0:16 ` Sinan Kaya 2017-09-24 0:16 ` Sinan Kaya 2017-10-11 22:06 ` Bjorn Helgaas 2017-10-11 22:06 ` Bjorn Helgaas 2017-10-11 22:06 ` Bjorn Helgaas 2017-10-12 16:48 ` Sinan Kaya 2017-10-12 16:48 ` Sinan Kaya 2017-10-16 12:51 ` Sinan Kaya 2017-10-16 12:51 ` Sinan Kaya 2017-09-24 0:16 ` [PATCH 5/5] PCI: add device wait after slot and bus reset Sinan Kaya 2017-09-24 0:16 ` Sinan Kaya 2017-09-24 0:20 ` Sinan Kaya 2017-09-24 0:20 ` Sinan Kaya 2017-10-11 22:08 ` [PATCH 1/5] PCI: protect restore with device lock to be consistent Bjorn Helgaas 2017-10-11 22:08 ` Bjorn Helgaas 2017-10-12 16:39 ` Sinan Kaya 2017-10-12 16:39 ` Sinan Kaya
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