Re: [PATCH v2] Bluetooth: btusb: using big-endian definition for board_id in struct qca_version

From: Marcel Holtmann
Date: Wed Nov 03 2021 - 10:24:59 EST


Hi Tim,

> As we name nvm file by using big-endian for boardID, so align host with it.
>
> Signed-off-by: Tim Jiang <tjiang@xxxxxxxxxxxxxx>
> ---
> drivers/bluetooth/btusb.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> index 46d892bbde62..08a1c6d8390f 100644
> --- a/drivers/bluetooth/btusb.c
> +++ b/drivers/bluetooth/btusb.c
> @@ -2883,7 +2883,7 @@ struct qca_version {
> __le32 rom_version;
> __le32 patch_version;
> __le32 ram_version;
> - __le16 board_id;
> + __be16 board_id;
> __le16 flag;
> __u8 reserved[4];
> } __packed;
> @@ -3072,7 +3072,7 @@ static void btusb_generate_qca_nvm_name(char *fwname, size_t max_size,
> u16 flag = le16_to_cpu(ver->flag);
>
> if (((flag >> 8) & 0xff) == QCA_FLAG_MULTI_NVM) {
> - u16 board_id = le16_to_cpu(ver->board_id);
> + u16 board_id = be16_to_cpu(ver->board_id);
> const char *variant;

my original comment still stands. Are you sure you are doing this correctly. The in-memory layout of your NVM is mixed little-endian and big-endian? Really? Or do you want to convert back from host endian to big endian?

You commit message text suggest that you have to do this:

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 46d892bbde62..55a33a5fea56 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -3090,7 +3090,7 @@ static void btusb_generate_qca_nvm_name(char *fwname, size_t max_size,
rom_version, variant);
} else {
snprintf(fwname, max_size, "qca/nvm_usb_%08x%s_%04x.bin",
- rom_version, variant, board_id);
+ rom_version, variant, cpu_to_be16(board_id));
}
} else {
snprintf(fwname, max_size, "qca/nvm_usb_%08x.bin”,

And really, I can not do this anymore. Write lengthy commit messages explaining your change in detail. I am not looking a patches anymore until they have a proper paragraph explaining the change and why it is correct.

Also this change had v16 before I merged and even in that version I had to fix issues. Please stop wasting my time. I have no idea why this wasn’t caught earlier. It is a fundamental flaw. I am close to just reverting the previous patch since it seems it clearly needs more testing.

Regards

Marcel