The ACPI EC address space handler currently only supports
reading/writing 8 bit values. Some firmware implementations however
want to access for example 16 bit values, which is prefectly legal
according to the ACPI spec.
Add support for reading/writing such values.
Tested on a Dell Inspiron 3505 and a Asus Prime B650-Plus.
Signed-off-by: Armin Wolf <[email protected]>
---
Changes since v1:
- use BITS_PER_BYTE
- validate that number of bytes to read/write does not overflow the
address
---
drivers/platform/x86/wmi.c | 47 ++++++++++++++++++++++++++++++--------
1 file changed, 37 insertions(+), 10 deletions(-)
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 1920e115da89..e542aef825a3 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -1153,6 +1153,32 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
return 0;
}
+static int ec_read_multiple(u8 address, u8 *buffer, size_t bytes)
+{
+ int i, ret;
+
+ for (i = 0; i < bytes; i++) {
+ ret = ec_read(address + i, &buffer[i]);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ec_write_multiple(u8 address, u8 *buffer, size_t bytes)
+{
+ int i, ret;
+
+ for (i = 0; i < bytes; i++) {
+ ret = ec_write(address + i, buffer[i]);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
/*
* WMI can have EmbeddedControl access regions. In which case, we just want to
* hand these off to the EC driver.
@@ -1162,27 +1188,28 @@ acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
u32 bits, u64 *value,
void *handler_context, void *region_context)
{
- int result = 0;
- u8 temp = 0;
+ int bytes = bits / BITS_PER_BYTE;
+ int ret;
+
+ if (!value)
+ return AE_NULL_ENTRY;
- if ((address > 0xFF) || !value)
+ if (bytes > sizeof(*value))
return AE_BAD_PARAMETER;
- if (function != ACPI_READ && function != ACPI_WRITE)
+ if (address > U8_MAX || address + bytes > U8_MAX)
return AE_BAD_PARAMETER;
- if (bits != 8)
+ if (function != ACPI_READ && function != ACPI_WRITE)
return AE_BAD_PARAMETER;
if (function == ACPI_READ) {
- result = ec_read(address, &temp);
- *value = temp;
+ ret = ec_read_multiple(address, (u8 *)value, bytes);
} else {
- temp = 0xff & *value;
- result = ec_write(address, temp);
+ ret = ec_write_multiple(address, (u8 *)value, bytes);
}
- switch (result) {
+ switch (ret) {
case -EINVAL:
return AE_BAD_PARAMETER;
case -ENODEV:
--
2.39.2
If an error code other than EINVAL, ENODEV or ETIME is returned
by ec_read()/ec_write(), then AE_OK is wrongly returned.
Fix this by only returning AE_OK if the return code is 0, and
return AE_ERROR otherwise.
Tested on a Dell Inspiron 3505 and a Asus Prime B650-Plus.
Reviewed-by: Hans de Goede <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Armin Wolf <[email protected]>
---
drivers/platform/x86/wmi.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index e542aef825a3..ad82a96ed145 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -1216,8 +1216,10 @@ acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
return AE_NOT_FOUND;
case -ETIME:
return AE_TIME;
- default:
+ case 0:
return AE_OK;
+ default:
+ return AE_ERROR;
}
}
--
2.39.2
On Thu, 7 Mar 2024, Armin Wolf wrote:
> The ACPI EC address space handler currently only supports
> reading/writing 8 bit values. Some firmware implementations however
> want to access for example 16 bit values, which is prefectly legal
> according to the ACPI spec.
>
> Add support for reading/writing such values.
>
> Tested on a Dell Inspiron 3505 and a Asus Prime B650-Plus.
>
> Signed-off-by: Armin Wolf <[email protected]>
> @@ -1162,27 +1188,28 @@ acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
> u32 bits, u64 *value,
> void *handler_context, void *region_context)
> {
> - int result = 0;
> - u8 temp = 0;
> + int bytes = bits / BITS_PER_BYTE;
> + int ret;
> +
> + if (!value)
> + return AE_NULL_ENTRY;
>
> - if ((address > 0xFF) || !value)
> + if (bytes > sizeof(*value))
> return AE_BAD_PARAMETER;
>
> - if (function != ACPI_READ && function != ACPI_WRITE)
> + if (address > U8_MAX || address + bytes > U8_MAX)
This doesn't look correct. With address = 0xff and bits = 8 this will
return AE_BAD_PARAMETER, is that intensional?
--
i.
Am 08.03.24 um 09:01 schrieb Ilpo Järvinen:
> On Thu, 7 Mar 2024, Armin Wolf wrote:
>
>> The ACPI EC address space handler currently only supports
>> reading/writing 8 bit values. Some firmware implementations however
>> want to access for example 16 bit values, which is prefectly legal
>> according to the ACPI spec.
>>
>> Add support for reading/writing such values.
>>
>> Tested on a Dell Inspiron 3505 and a Asus Prime B650-Plus.
>>
>> Signed-off-by: Armin Wolf <[email protected]>
>> @@ -1162,27 +1188,28 @@ acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
>> u32 bits, u64 *value,
>> void *handler_context, void *region_context)
>> {
>> - int result = 0;
>> - u8 temp = 0;
>> + int bytes = bits / BITS_PER_BYTE;
>> + int ret;
>> +
>> + if (!value)
>> + return AE_NULL_ENTRY;
>>
>> - if ((address > 0xFF) || !value)
>> + if (bytes > sizeof(*value))
>> return AE_BAD_PARAMETER;
>>
>> - if (function != ACPI_READ && function != ACPI_WRITE)
>> + if (address > U8_MAX || address + bytes > U8_MAX)
> This doesn't look correct. With address = 0xff and bits = 8 this will
> return AE_BAD_PARAMETER, is that intensional?
>
You are absolutely correct, i will send an updated series soon.
Thanks,
Armin Wolf