On 10/23/25 5:04 AM, Greg Kroah-Hartman wrote:
On Wed, Oct 22, 2025 at 12:57:57PM +0530, Ayush Singh wrote:
According to the Greybus Spec published here [0], the Greybus firmware download find firmware request should have both tag and format as request arguments. However, currently, the linux kernel seems to have defined this request incorrectly since format is missing.
Odd, I don't remember that at all, but it was changed here: https://github.com/projectara/greybus-spec/commit/773b9e0d6cc84a3c7a9f79ea35...
maybe we never actually implemented it?
To be fair, it was the very last commit to the spec before the program was canceled. So it would not surprise me too much if the kernel commit didn't get made.
-Alex
The patch adds format to request and am using it as the file extension of the firmware.
Signed-off-by: Ayush Singh ayush@beagleboard.org
According to the Greybus Spec published here [0], the Greybus firmware download find firmware request should have both tag and format as request arguments. However, currently, the linux kernel seems to have defined this request incorrectly since format is missing.
The patch adds format to request and am using it as the file extension of the firmware.
I came across the bug while working on greybus-for-zephyr [1], to get it ready for upstreaming as zephyr module.
Open Questions
- Handle empty format
Not sure what to do in case format is just NULL. Should the request fail? There is no reason to not support firmware without extension. So personally, I don't think it should be treated as error.
As this is a AP-specific thing, it's whatever you want to do I think. You can handle NULL there, or anything else, it's up to the firmware and userspace to coordinate this, right?
drivers/staging/greybus/fw-download.c | 31 ++++++++++++++++++++++++------- include/linux/greybus/greybus_protocols.h | 2 ++ 2 files changed, 26 insertions(+), 7 deletions(-)
diff --git a/drivers/staging/greybus/fw-download.c b/drivers/staging/greybus/fw-download.c index 9a09bd3af79ba0dcf7efa683f4e86246bcd473a5..06f1be8f3121e29551ea8416d5ee2666339b2fe3 100644 --- a/drivers/staging/greybus/fw-download.c +++ b/drivers/staging/greybus/fw-download.c @@ -159,7 +159,7 @@ static int exceeds_release_timeout(struct fw_request *fw_req) /* This returns path of the firmware blob on the disk */ static struct fw_request *find_firmware(struct fw_download *fw_download,
const char *tag)
const char *tag, const char *format)@@ -178,10 +178,17 @@ static struct fw_request *find_firmware(struct fw_download *fw_download, } fw_req->firmware_id = ret;
- snprintf(fw_req->name, sizeof(fw_req->name),
FW_NAME_PREFIX "%08x_%08x_%08x_%08x_%s.tftf",intf->ddbl1_manufacturer_id, intf->ddbl1_product_id,intf->vendor_id, intf->product_id, tag);
- if (strnlen(format, GB_FIRMWARE_FORMAT_MAX_SIZE) == 0) {
snprintf(fw_req->name, sizeof(fw_req->name),FW_NAME_PREFIX "%08x_%08x_%08x_%08x_%s",intf->ddbl1_manufacturer_id, intf->ddbl1_product_id,intf->vendor_id, intf->product_id, tag);- } else {
snprintf(fw_req->name, sizeof(fw_req->name),FW_NAME_PREFIX "%08x_%08x_%08x_%08x_%s.%s",intf->ddbl1_manufacturer_id, intf->ddbl1_product_id,intf->vendor_id, intf->product_id, tag, format);- }
dev_info(fw_download->parent, "Requested firmware package '%s'\n", fw_req->name); @@ -225,7 +232,7 @@ static int fw_download_find_firmware(struct gb_operation *op) struct gb_fw_download_find_firmware_request *request; struct gb_fw_download_find_firmware_response *response; struct fw_request *fw_req;
- const char *tag;
- const char *tag, *format;
if (op->request->payload_size != sizeof(*request)) { dev_err(fw_download->parent, @@ -245,7 +252,17 @@ static int fw_download_find_firmware(struct gb_operation *op) return -EINVAL; }
- fw_req = find_firmware(fw_download, tag);
- format = (const char *)request->format;
- /* firmware_format must be null-terminated */
- if (strnlen(format, GB_FIRMWARE_FORMAT_MAX_SIZE) ==
GB_FIRMWARE_FORMAT_MAX_SIZE) {dev_err(fw_download->parent,"firmware-format is not null-terminated\n");return -EINVAL;- }
- fw_req = find_firmware(fw_download, tag, format); if (IS_ERR(fw_req)) return PTR_ERR(fw_req);
diff --git a/include/linux/greybus/greybus_protocols.h b/include/linux/greybus/greybus_protocols.h index 820134b0105c2caf8cea3ff0985c92d48d3a2d4c..48d91154847dbc7d3c01081eadc69f96dbe41a9f 100644 --- a/include/linux/greybus/greybus_protocols.h +++ b/include/linux/greybus/greybus_protocols.h @@ -214,10 +214,12 @@ struct gb_apb_request_cport_flags { #define GB_FW_DOWNLOAD_TYPE_RELEASE_FIRMWARE 0x03 #define GB_FIRMWARE_TAG_MAX_SIZE 10 +#define GB_FIRMWARE_FORMAT_MAX_SIZE 10 /* firmware download find firmware request/response */ struct gb_fw_download_find_firmware_request { __u8 firmware_tag[GB_FIRMWARE_TAG_MAX_SIZE];
- __u8 format[GB_FIRMWARE_FORMAT_MAX_SIZE];
Build issues asside (see the 0-day bot report), I am loath to change a user api like this at the moment, without some sort of guarantee that this isn't going to break anything.
But, these days, I think your implementation might be one of the few "real" greybus users that is still alive. The old phones that used the protocol are no longer being sold from what I can tell, and the "greybus over IP" stuff didn't actually get used anywhere outside of cool demos that I know of.
So we might be ok? Or, can you live without any such "format" need? Have you handled downloading firmware already without this?
thanks,
greg k-h