[PATCH v3] 8250_pci: add -ENODEV code for Intel EG20T PCH

[PATCH v3] 8250_pci: add -ENODEV code for Intel EG20T PCH

[Tomoya MORINAGA]

Intel EG20T PCH has UART device which is compatible with 8250.
Currently, with general configuration, the PCH UART driver is not loaded but
8250 standard driver is loaded.
Therefore, in case of using PCH UART driver, need to disable 8250 pci function.
However, this procedure is not best solution.
This patch, in 8250_pci, if the device is the PCH or the family IOH,
'-ENODEV' is returned.
As a result, disabling 8250-pci processing becomes unnecessary.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
---
V3: add own init() and set the init() to quirk table.

V2: Delete #ifdef CONFIG_SERIAL_PCH_UART ~ #endif
    Use quirk table structure
---
 drivers/tty/serial/8250_pci.c |   55 +++++++++++++++++++++++++++++++++++++++++
 1 files changed, 55 insertions(+), 0 deletions(-)

diff --git a/drivers/tty/serial/8250_pci.c b/drivers/tty/serial/8250_pci.c
index 738cec9..256c77e 100644
--- a/drivers/tty/serial/8250_pci.c
+++ b/drivers/tty/serial/8250_pci.c
@@ -988,6 +988,11 @@ static int skip_tx_en_setup(struct serial_private *priv,
 	return pci_default_setup(priv, board, port, idx);
 }
 
+static int pci_eg20tpch_init(struct pci_dev *dev)
+{
+	return -ENODEV;
+}
+
 /* This should be in linux/pci_ids.h */
 #define PCI_VENDOR_ID_SBSMODULARIO	0x124B
 #define PCI_SUBVENDOR_ID_SBSMODULARIO	0x124B
@@ -1430,6 +1435,56 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
 		.init		= pci_oxsemi_tornado_init,
 		.setup		= pci_default_setup,
 	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8811,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8812,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8813,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = PCI_VENDOR_ID_INTEL,
+		.device         = 0x8814,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8027,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8028,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x8029,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x800C,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x800D,
+		.init		= pci_eg20tpch_init,
+	},
+	{
+		.vendor         = 0x10DB,
+		.device         = 0x800D,
+		.init		= pci_eg20tpch_init,
+	},
 	/*
 	 * Default "match everything" terminator entry
 	 */
-- 
1.7.4

Re: [PATCH v3] 8250_pci: add -ENODEV code for Intel EG20T PCH

[Michał Mirosław]

On Tue, May 31, 2011 at 11:22:39AM +0900, Tomoya MORINAGA wrote:
> Intel EG20T PCH has UART device which is compatible with 8250.
> Currently, with general configuration, the PCH UART driver is not loaded but
> 8250 standard driver is loaded.
> Therefore, in case of using PCH UART driver, need to disable 8250 pci function.
> However, this procedure is not best solution.
> This patch, in 8250_pci, if the device is the PCH or the family IOH,
> '-ENODEV' is returned.
> As a result, disabling 8250-pci processing becomes unnecessary.
[...]
> +static int pci_eg20tpch_init(struct pci_dev *dev)
> +{
> +	return -ENODEV;
> +}

You could name it just return_ENODEV() or similar and then while looking
at the device-id table you would know right away what this entry is doing.

Best Regards,
Michał Mirosław
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v3] 8250_pci: add -ENODEV code for Intel EG20T PCH

[Alan Cox]

> V2: Delete #ifdef CONFIG_SERIAL_PCH_UART ~ #endif
>     Use quirk table structure

I would keep the ifdef. We want to fall back and if we don't do that
then users currently using 8250 will have their system break on upgrade
which is not acceptable really.

So I'd keep with the patch below but:

> +static int pci_eg20tpch_init(struct pci_dev *dev)
> +{
#if !defined(CONFIG_SERIAL_PCH_UART) && ...
> +	return -ENODEV;
#else
	return 0;
#endif

> +}


I don't think we can avoid that one ifdef without breakage.