Hi Trey,
On Tue, Jul 9, 2024 at 1:34 PM Ramsay, Trey <Trey.Ramsay@xxxxxxxx> wrote:
>
> Bluez Maintainers,
> Here is a fix for attribute writes not working in src/shared/gatt-db.c. The prep_write_complete_cb was not getting called. The attrib->write_func code block should not be called when len is 0
>
> commit 5a9baa10d4fde7ca8ab88ecd68e17671c33cb587 (HEAD -> gat-db, master)
> Author: Trey_Ramsay <trey_ramsay@xxxxxxxx>
> Date: Fri May 31 15:39:27 2024 -0500
>
> shared/gatt-db: Prepare Write req error BT_ATT_ERROR_UNLIKELY
>
> Fixes Prepare Write req error: BT_ATT_ERROR_UNLIKELY
>
> ATT: Error (0x01)
> Error: Unlikely error (14)
> Prepare Write req (0x16) on handle 0x0069
>
> The prep_write_complete_cb was not getting called
> The attrib->write_func code block does not need to be called when len is 0
This doesn't sound quite right, 0 length still needs to be passed to
the attribute to confirm since we don't know if it could be a
procedure or not. Can you explain what attribute is being written and
if it could be due to the application not responding and the procedure
timing out (e.g. write_timeout is called?), perhaps if you can paste a
btmon trace as well that could help checking what attribute it is
trying to use prepare write.
> diff --git a/src/shared/gatt-db.c b/src/shared/gatt-db.c
> index 2c8e7d31e..678aef4cf 100644
> --- a/src/shared/gatt-db.c
> +++ b/src/shared/gatt-db.c
> @@ -2127,6 +2127,10 @@ bool gatt_db_attribute_write(struct gatt_db_attribute *attrib, uint16_t offset,
> if (!attrib || (!func && attrib->write_func))
> return false;
>
> + /* Nothing to write just skip */
> + if (len == 0)
> + goto done;
> +
> if (attrib->write_func) {
> struct pending_write *p;
>
> @@ -2162,10 +2166,6 @@ bool gatt_db_attribute_write(struct gatt_db_attribute *attrib, uint16_t offset,
> return true;
> }
>
> - /* Nothing to write just skip */
> - if (len == 0)
> - goto done;
> -
> /* For values stored in db allocate on demand */
> if (!attrib->value || offset >= attrib->value_len ||
> len > (unsigned) (attrib->value_len - offset)) {
>
>
>
> -----Original Message-----
> From: Ramsay, Trey <Trey.Ramsay@xxxxxxxx>
> Sent: Thursday, June 20, 2024 1:58 PM
> To: linux-bluetooth@xxxxxxxxxxxxxxx
> Subject: [PATCH] ATT: Error (0x01) - Error: Unlikely error (14) Prepare Write req (0x16)
>
>
> Bluez Maintainers
> Here is a fix for attribute writes not working in src/shared/gatt-db.c
>
> https://urldefense.com/v3/__https://github.com/tramsay/bluez-tramsay/commit/246bc960629dff34e744c728f048e9f50f1a005d__;!!LpKI!jkJYamzU8bOdd1qt-sWpj6gy1YwS30UyamHLUJj9Uy0UecrB6QxvCdSWFAUH7Dvq2wVJqu1C5jjoX5amywJH$ [github[.]com]
>
> shared/gatt-db: Prepare Write req error BT_ATT_ERROR_UNLIKELY Fixes Prepare Write req error: BT_ATT_ERROR_UNLIKELY
>
> ATT: Error (0x01)
> Error: Unlikely error (14)
> Prepare Write req (0x16) on handle 0x0069
>
> The prep_write_complete_cb was not getting called The attrib->write_func code block should not be called when len is 0
>
--
Luiz Augusto von Dentz
