Re: [PATCH v4 5/9] misc: amd-sbi: Add support for mailbox error codes

From: Gupta, Akshay
Date: Tue Oct 15 2024 - 05:14:24 EST


On 10/13/2024 8:49 PM, Greg KH wrote:
Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.


On Thu, Sep 12, 2024 at 07:08:06AM +0000, Akshay Gupta wrote:
--- a/include/uapi/misc/amd-apml.h
+++ b/include/uapi/misc/amd-apml.h
@@ -38,6 +38,10 @@ struct apml_message {
__u32 mb_in[2];
__u8 reg_in[8];
} data_in;
+ /*
+ * Error code is returned in case of soft mailbox
+ */
+ __u32 fw_ret_code;
} __attribute__((packed));
You can not just randomly change the size of a user/kernel structure
like this, what just broke because of this?

confused,

The changes are not because of anything is broken, we support 3 different protocol under 1 IOCTL using the same structure. I split the patch to make it easy to review.
Modification in patch 4, is only for the existing code. This patch (patch 5) has additional functionality, so we do not want add multiple changes in single patch (patch 4).

The changes done in patches are as follows:

Patch 4:

- Adding basic structure as per current protocol in upstream kernel

Patch 5:

- Adding additional error code from PMFW.

Patch 6:

- Add changes required to support CPUID protocol

Patch 7:

- Comments modification for MCAMSR protocol (structure remains same as CPUID)

greg k-h