Re: [PATCH] i2c-scmi: Quirk to work on IBM machines with broken BIOSes

Crane Cai
2009-10-22T07:19:24Z

Hi Darrick,

On Wed, Oct 21, 2009 at 10:37:33AM -0700, Darrick J. Wong wrote:
> The problem is that the BIOS does not provide an HID for the SMBus object at
> all...
Yes, I now indeed understand. Orignal I guess you manually change IBM SMBus HID,
now I know you add a HID for it.
> >
> > Can you elaborate on your suggestion?
> >
This patch below represents my meanings:
*) add a new HID for IBM SMBus CMI devices
*) add methods for IBM SMBus CMI devices as you did
*) hook different HID with different control methods set
It may be more smooth for i2c-scmi, please consider.

---
drivers/i2c/busses/i2c-scmi.c | 31 +++++++++++++++++++++++--------
1 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-scmi.c b/drivers/i2c/busses/i2c-scmi.c
index b4a55d4..2c5b629 100644
--- a/drivers/i2c/busses/i2c-scmi.c
+++ b/drivers/i2c/busses/i2c-scmi.c
@@ -33,6 +33,7 @@ struct acpi_smbus_cmi {
u8 cap_info:1;
u8 cap_read:1;
u8 cap_write:1;
+ struct smbus_methods_t *methods;
};

static const struct smbus_methods_t smbus_methods = {
@@ -41,8 +42,16 @@ static const struct smbus_methods_t smbus_methods = {
.mt_sbw = "_SBW",
};

+/* Some IBM BIOSes omit the leading underscore */
+static const struct smbus_methods_t ibm_smbus_methods = {
+ .mt_info = "SBI_",
+ .mt_sbr = "SBR_",
+ .mt_sbw = "SBW_",
+};
+
static const struct acpi_device_id acpi_smbus_cmi_ids[] = {
- {"SMBUS01", 0},
+ {"SMBUS01", (kernel_ulong_t)&smbus_methods},
+ {"SMBUSIBM", (kernel_ulong_t)&ibm_smbus_methods},
{"", 0}
};

@@ -150,11 +159,11 @@ acpi_smbus_cmi_access(struct i2c_adapter *adap, u16 addr, unsigned short flags,

if (read_write == I2C_SMBUS_READ) {
protocol |= ACPI_SMBUS_PRTCL_READ;
- method = smbus_methods.mt_sbr;
+ method = smbus_cmi->methods->mt_sbr;
input.count = 3;
} else {
protocol |= ACPI_SMBUS_PRTCL_WRITE;
- method = smbus_methods.mt_sbw;
+ method = smbus_cmi->methods->mt_sbw;
input.count = 5;
}

@@ -290,13 +299,13 @@ static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,
union acpi_object *obj;
acpi_status status;

- if (!strcmp(name, smbus_methods.mt_info)) {
+ if (!strcmp(name, smbus_cmi->methods->mt_info)) {
status = acpi_evaluate_object(smbus_cmi->handle,
- smbus_methods.mt_info,
+ smbus_cmi->methods->mt_info,
NULL, &buffer);
if (ACPI_FAILURE(status)) {
ACPI_ERROR((AE_INFO, "Evaluating %s: %i",
- smbus_methods.mt_info, status));
+ smbus_cmi->methods->mt_info, status));
return -EIO;
}

@@ -319,9 +328,9 @@ static int acpi_smbus_cmi_add_cap(struct acpi_smbus_cmi *smbus_cmi,

kfree(buffer.pointer);
smbus_cmi->cap_info = 1;
- } else if (!strcmp(name, smbus_methods.mt_sbr))
+ } else if (!strcmp(name, smbus_cmi->methods->mt_sbr))
smbus_cmi->cap_read = 1;
- else if (!strcmp(name, smbus_methods.mt_sbw))
+ else if (!strcmp(name, smbus_cmi->methods->mt_sbw))
smbus_cmi->cap_write = 1;
else
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Unsupported CMI method: %s\n",
@@ -349,6 +358,7 @@ static acpi_status acpi_smbus_cmi_query_methods(acpi_handle handle, u32 level,
static int acpi_smbus_cmi_add(struct acpi_device *device)
{
struct acpi_smbus_cmi *smbus_cmi;
+ struct acpi_device_id *id = (struct acpi_device_id *)acpi_smbus_cmi_ids;

smbus_cmi = kzalloc(sizeof(struct acpi_smbus_cmi), GFP_KERNEL);
if (!smbus_cmi)
@@ -362,6 +372,11 @@ static int acpi_smbus_cmi_add(struct acpi_device *device)
smbus_cmi->cap_read = 0;
smbus_cmi->cap_write = 0;

+ for (; id->id[0]; id++)
+ if (!strcmp((char *) id->id, acpi_device_hid(device)))
+ smbus_cmi->methods =
+ (struct smbus_methods_t *) id->driver_data;
+
acpi_walk_namespace(ACPI_TYPE_METHOD, smbus_cmi->handle, 1,
acpi_smbus_cmi_query_methods, smbus_cmi, NULL);
---

--
Best Regards,
- Crane