From: Thomas Gleixner <tglx@linutronix.de>
To: Frank Wunderlich <frank-w@public-files.de>
Cc: Ryder Lee <ryder.lee@mediatek.com>, Marc Zyngier <maz@kernel.org>,
linux-kernel@vger.kernel.org, Bjorn Helgaas <bhelgaas@google.com>,
linux-mediatek@lists.infradead.org, linux-pci@vger.kernel.org,
Matthias Brugger <matthias.bgg@gmail.com>,
Frank Wunderlich <linux@fw-web.de>
Subject: Re: Aw: Re: Re: [PATCH] pci: mediatek: fix warning in msi.h
Date: Thu, 05 Nov 2020 00:14:20 +0100 [thread overview]
Message-ID: <87h7q4lnoz.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <trinity-1d7f8900-10db-40c0-a0aa-47bb99ed84cd-1604508571909@3c-app-gmx-bs02>
Frank,
On Wed, Nov 04 2020 at 17:49, Frank Wunderlich wrote:
>> Von: "Thomas Gleixner" <tglx@linutronix.de>
>> Any architecture which selects PCI_MSI_ARCH_FALLBACKS and does not have
>> irqdomain support runs into:
>>
>> if (!d)
>> bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
>>
>> which in turn makes pci_msi_supported() return 0 and consequently makes
>> pci_enable_msi[x]() fail.
>
> i'm not that deep into this, but just my thoughts...you are the experts :)
>
> checking for PCI_MSI_ARCH_FALLBACKS here does not help?
>
> something like this:
>
> #ifndef PCI_MSI_ARCH_FALLBACKS
> if (!d)
> bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
> #endif
TBH, that's butt ugly. So after staring long enough into the PCI code I
came up with a way to transport that information to the probe code.
That allows a particular device to say 'I can't do MSI' and at the same
time keeps the warning machinery intact which tells us that a particular
host controller driver is broken.
Uncompiled and untested as usual :)
Thanks,
tglx
---
drivers/pci/controller/pcie-mediatek.c | 4 ++++
drivers/pci/probe.c | 3 +++
include/linux/pci.h | 1 +
3 files changed, 8 insertions(+)
--- a/drivers/pci/controller/pcie-mediatek.c
+++ b/drivers/pci/controller/pcie-mediatek.c
@@ -143,6 +143,7 @@ struct mtk_pcie_port;
* struct mtk_pcie_soc - differentiate between host generations
* @need_fix_class_id: whether this host's class ID needed to be fixed or not
* @need_fix_device_id: whether this host's device ID needed to be fixed or not
+ * @no_msi: Bridge has no MSI support
* @device_id: device ID which this host need to be fixed
* @ops: pointer to configuration access functions
* @startup: pointer to controller setting functions
@@ -151,6 +152,7 @@ struct mtk_pcie_port;
struct mtk_pcie_soc {
bool need_fix_class_id;
bool need_fix_device_id;
+ bool no_msi;
unsigned int device_id;
struct pci_ops *ops;
int (*startup)(struct mtk_pcie_port *port);
@@ -1084,6 +1086,7 @@ static int mtk_pcie_probe(struct platfor
host->ops = pcie->soc->ops;
host->sysdata = pcie;
+ host->no_msi = pcie->soc->no_msi;
err = pci_host_probe(host);
if (err)
@@ -1173,6 +1176,7 @@ static const struct dev_pm_ops mtk_pcie_
};
static const struct mtk_pcie_soc mtk_pcie_soc_v1 = {
+ .no_msi = true,
.ops = &mtk_pcie_ops,
.startup = mtk_pcie_startup_port,
};
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -889,6 +889,9 @@ static int pci_register_host_bridge(stru
if (!bus)
return -ENOMEM;
+ if (bridge->no_msi)
+ bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
+
bridge->bus = bus;
/* Temporarily move resources off the list */
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -545,6 +545,7 @@ struct pci_host_bridge {
unsigned int native_dpc:1; /* OS may use PCIe DPC */
unsigned int preserve_config:1; /* Preserve FW resource setup */
unsigned int size_windows:1; /* Enable root bus sizing */
+ unsigned int no_msi:1; /* Bridge has no MSI support */
/* Resource alignment requirements */
resource_size_t (*align_resource)(struct pci_dev *dev,
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next prev parent reply other threads:[~2020-11-05 4:54 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-31 14:03 [PATCH] pci: mediatek: fix warning in msi.h Frank Wunderlich
2020-10-31 21:49 ` Thomas Gleixner
2020-11-01 9:25 ` Frank Wunderlich
2020-11-01 11:17 ` Thomas Gleixner
2020-11-01 11:43 ` Marc Zyngier
2020-11-01 15:58 ` Aw: " Frank Wunderlich
2020-11-01 17:54 ` Ryder Lee
2020-11-01 18:27 ` Aw: " Frank Wunderlich
2020-11-01 21:47 ` Marc Zyngier
2020-11-01 22:27 ` Thomas Gleixner
2020-11-02 11:30 ` Marc Zyngier
2020-11-02 11:56 ` Aw: " Frank Wunderlich
2020-11-02 13:58 ` Marc Zyngier
2020-11-02 14:27 ` Aw: " Frank Wunderlich
2020-11-02 16:16 ` Aw: " Thomas Gleixner
2020-11-02 22:18 ` Thomas Gleixner
2020-11-03 9:54 ` Marc Zyngier
2020-11-03 10:16 ` Thomas Gleixner
2020-11-03 10:29 ` Marc Zyngier
2020-11-04 16:49 ` Aw: " Frank Wunderlich
2020-11-04 23:14 ` Thomas Gleixner [this message]
2020-11-05 9:20 ` Marc Zyngier
2020-11-05 13:59 ` Aw: " Frank Wunderlich
2020-11-05 23:00 ` Aw: " Thomas Gleixner
2020-11-06 9:43 ` Marc Zyngier
2020-11-21 16:12 ` Aw: " Frank Wunderlich
2021-01-03 13:08 ` Frank Wunderlich
2021-02-02 16:21 ` Frank Wunderlich
2020-11-03 10:31 ` Aw: " Thomas Gleixner
2020-11-03 11:41 ` Marc Zyngier
2020-11-03 14:23 ` Thomas Gleixner
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