From: Jiang Liu <jiang.liu@huawei.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jiang Liu <liuj97@gmail.com>, Don Dutile <ddutile@redhat.com>,
Yinghai Lu <yinghai@kernel.org>,
Taku Izumi <izumi.taku@jp.fujitsu.com>,
"Rafael J . Wysocki" <rjw@sisk.pl>,
Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>,
Yijing Wang <wangyijing@huawei.com>,
Keping Chen <chenkeping@huawei.com>,
<linux-kernel@vger.kernel.org>, <linux-pci@vger.kernel.org>
Subject: Re: [RFC PATCH 05/14] PCI: add access functions for PCIe capabilities to hide PCIe spec differences
Date: Wed, 11 Jul 2012 14:40:39 +0800 [thread overview]
Message-ID: <4FFD1FE7.6010504@huawei.com> (raw)
In-Reply-To: <CAErSpo4JrgU2RHoNDWcm13otgdKVXuGxahE0pbuAD73nZvTZFQ@mail.gmail.com>
On 2012-7-11 11:40, Bjorn Helgaas wrote:
>> Good point. Return success when reading unimplemented registeres, that
>> may simplify code. For we still should return -EINVAL when writing
>> unimplemented registers, right?
>
> Yeah, I guess it's OK to return -EINVAL when *writing* to an
> unimplemented register. Hopefully the caller is structured such that
> we don't even try to write in that case. It'd be interesting to audit
> the callers and explore that, but I haven't done that.
Hi Bjorn,
Seems it would be better to return error code for unimplemented
registers, otherwise following code will becomes more complex. A special
error code for unimplemented registers, such as -EIO?
static void rtl_disable_clock_request(struct pci_dev *pdev)
{
u16 ctl;
if (!pci_pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &ctl)) {
ctl &= ~PCI_EXP_LNKCTL_CLKREQ_EN;
pci_pcie_capability_write_word(pdev, PCI_EXP_LNKCTL, ctl);
}
}
next prev parent reply other threads:[~2012-07-11 6:44 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-04 7:44 [Resend with Ack][PATCH v1] PCI: allow acpiphp to handle PCIe ports without native PCIe hotplug capability Jiang Liu
2012-06-04 8:23 ` Kenji Kaneshige
2012-07-03 4:16 ` Bjorn Helgaas
2012-07-03 15:59 ` Bjorn Helgaas
2012-07-03 19:50 ` Don Dutile
2012-07-04 18:07 ` Bjorn Helgaas
2012-07-09 10:05 ` Jiang Liu
2012-07-09 17:05 ` Bjorn Helgaas
2012-07-04 2:52 ` Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 00/14] improve PCIe capabilities registers handling Jiang Liu
2012-07-10 18:44 ` Bjorn Helgaas
2012-07-10 15:54 ` [RFC PATCH 01/14] PCI: add pcie_flags into struct pci_dev to cache PCIe capabilities register Jiang Liu
2012-07-11 9:01 ` Taku Izumi
2012-07-11 14:27 ` Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 02/14] PCI: introduce pci_pcie_type(dev) to replace pci_dev->pcie_type Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 03/14] PCI: remove unused field pcie_type from struct pci_dev Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 04/14] PCI: refine and move pcie_cap_has_*() macros to include/linux/pci.h Jiang Liu
2012-07-10 18:49 ` Bjorn Helgaas
2012-07-10 15:54 ` [RFC PATCH 05/14] PCI: add access functions for PCIe capabilities to hide PCIe spec differences Jiang Liu
2012-07-10 18:35 ` Bjorn Helgaas
2012-07-11 3:07 ` Jiang Liu
2012-07-11 3:40 ` Bjorn Helgaas
2012-07-11 6:40 ` Jiang Liu [this message]
2012-07-11 17:52 ` Bjorn Helgaas
2012-07-12 2:56 ` Jiang Liu
2012-07-12 20:49 ` Bjorn Helgaas
2012-07-15 16:47 ` Jiang Liu
2012-07-16 17:29 ` Bjorn Helgaas
2012-07-16 18:57 ` Don Dutile
2012-07-17 0:09 ` Jiang Liu
2012-07-17 0:14 ` Bjorn Helgaas
2012-07-10 15:54 ` [RFC PATCH 06/14] PCI: use PCIe cap access functions to simplify PCI core implementation Jiang Liu
2012-07-10 18:35 ` Bjorn Helgaas
2012-07-11 2:49 ` Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 07/14] hotplug/PCI: use PCIe cap access functions to simplify implementation Jiang Liu
2012-07-10 18:35 ` Bjorn Helgaas
2012-07-10 15:54 ` [RFC PATCH 08/14] portdrv/PCI: " Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 09/14] pciehp/PCI: " Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 10/14] PME/PCI: " Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 11/14] AER/PCI: " Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 12/14] ASPM/PCI: " Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 13/14] r8169/PCI: " Jiang Liu
2012-07-10 15:54 ` [RFC PATCH 14/14] qib/PCI: " Jiang Liu
2012-08-15 19:12 ` [Resend with Ack][PATCH v1] PCI: allow acpiphp to handle PCIe ports without native PCIe hotplug capability Bjorn Helgaas
2012-08-16 15:15 ` Jiang Liu
2012-08-22 15:16 ` [PATCH v2] PCI: allow acpiphp to handle PCIe ports w/o " Jiang Liu
2012-09-24 22:10 ` Bjorn Helgaas
2012-09-25 15:16 ` Jiang Liu
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