Re: [PATCH 1/1] ata/sata_sil24: MSI support, disabled by default
From: Grant Grundler <hidden>
Date: 2009-11-16 17:48:14
Also in:
linux-ide
On Sun, Nov 15, 2009 at 10:19 PM, Vivek Mahajan [off-list ref] wrote:
quoted hunk ↗ jump to hunk
The following patch adds MSI support. Some platforms may have broken MSI, so those are defaulted to use legacy PCI interrupts. Signed-off-by: Vivek Mahajan <redacted> --- =C2=A0drivers/ata/sata_sil24.c | =C2=A0 =C2=A09 +++++++++ =C2=A01 files changed, 9 insertions(+), 0 deletions(-)diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c index e6946fc..1370df6 100644 --- a/drivers/ata/sata_sil24.c +++ b/drivers/ata/sata_sil24.c@@ -417,6 +417,10 @@ static struct ata_port_operations sil24_ops =3D {=C2=A0#endif =C2=A0}; +static int sata_sil24_msi; =C2=A0 =C2=A0/* Disable MSI */ +module_param_named(msi, sata_sil24_msi, bool, S_IRUGO); +MODULE_PARM_DESC(msi, "Enable MSI (Default: false)");
Vivek, Do we even still need the parameter? I'm thinking either MSI works with a chipset or it doesn't. The kernel has globals to "know" which state is true. If the parameter is needed, when this driver is compiled into the kernel, h= ow is "msi" parameter specified? I think the parameter needs to be documented and fit in with other "msi" parameters. See "nomsi" in Documentation/kernel-parameters.txt. If you want to keep this module parameter, can I suggest calling the exported parameter "sata_sil24_msi"? I'm not able to test this since the chipset I have sata_sil24 devices plugged into don't support MSI (older AMD/Nvidia chipset). :(
quoted hunk ↗ jump to hunk
+ =C2=A0/* =C2=A0* Use bits 30-31 of port_flags to encode available port numbers. =C2=A0* Current maxium is 4.@@ -1340,6 +1344,11 @@ static int sil24_init_one(struct pci_dev *pdev, co=
nst struct pci_device_id *ent)
=C2=A0 =C2=A0 =C2=A0 =C2=A0sil24_init_controller(host);
+ =C2=A0 =C2=A0 =C2=A0 if (sata_sil24_msi && !!pci_msi_enable(pdev)) {
+ =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 dev_printk(KERN_INFO, =&pdev->dev, "Using MSI\n");
+ =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 pci_intx(pdev, 0);
pci_intx() isn't documented in MSI-HOWTO.txt - because it's already called=
:
pci_msi_enable() -> pci_msi_enable_block() -> msi_capability_init()
-> pci_intx_for_msi(dev, 0) -> pci_intx(pdev, 0);
(thanks to willy (Mathew Wilcox) for pointing me at
msi_capability_init() - I overlooked it)
Please add "Reviewed-by: Grant Grundler [off-list ref]" once the
variable name is changed and the pci_intx() call is removed.
cheers,
grant
+ =C2=A0 =C2=A0 =C2=A0 } + =C2=A0 =C2=A0 =C2=A0 =C2=A0pci_set_master(pdev); =C2=A0 =C2=A0 =C2=A0 =C2=A0return ata_host_activate(host, pdev->irq, sil2=
4_interrupt, IRQF_SHARED,
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=
=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 &sil24_sht);
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