Re: [PATCH v2] Bluetooth: btusb: fixed command length alignment on Intel 8260

[Tedd Ho-Jeong An <tedd.an@intel.com>]

Hi Marcel,

On Sat, 6 Jun 2015 08:15:01 +0200
Marcel Holtmann <marcel@holtmann.org> wrote:

> Hi Tedd,
> 
> > This patch fixes the command length alignment issue for Intel Bluetooth
> > 8260.
> > 
> > The length of parameters in the firmware downloading command must be
> > multiplication of 4. If not, the command must append Intel_NOP command
> > with extra parameters, zeros, at the end, and the firmware file is
> > already included Intel_NOP command for alignment.
> > 
> > This patch checks the next command and if the next command is Intel_NOP
> > command, it reads the Intel_NOP command and send them together.
> > 
> > For example, if the data from the firmware file looks like this:
> > 8E FC 03 11 22 33 02 FC 03 00 00 00
> > 
> > Previously, btusb sends two commands:
> > 09 FC 06 8E FC 03 11 22 33
> > 09 FC 06 02 FC 03 00 00 00
> > 
> > This won't work because the length of parameters are 6 which violates
> > the 4 byte alignment.
> > 
> > This patch will append them together and send as one command:
> > 09 FC 0B 8E FC 03 11 22 33 02 FC 03 00 00 00
> 
> I assume this should be 09 FC 0C to indicate 12 bytes of payload.
> 
> > Signed-off-by: Tedd Ho-Jeong An <tedd.an@intel.com>
> > ---
> > drivers/bluetooth/btusb.c | 16 ++++++++++++++++
> > 1 file changed, 16 insertions(+)
> > 
> > diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
> > index d21f3b4..13b9969 100644
> > --- a/drivers/bluetooth/btusb.c
> > +++ b/drivers/bluetooth/btusb.c
> > @@ -2541,6 +2541,22 @@ static int btusb_setup_intel_new(struct hci_dev *hdev)
> > 
> > 		cmd_len = sizeof(*cmd) + cmd->plen;
> > 
> > +		/* The parameter length of secure send command should be a
> > +		 * multiplication of 4. If it is not, it needs to append
> > +		 * Intel_NOP command with arbitrary number of parameters (zeros)
> > +		 * to meet the 4 byte alignment.
> > +		 * The FW file has already formatted with this. So if the next
> > +		 * command is Intel_NOP then send them together.
> > +		 */
> > +		cmd = (void *)(fw_ptr + cmd_len);
> > +		if (le16_to_cpu(cmd->opcode) == 0xfc02) {
> > +			BT_DBG("%s: Updated cmd to include Intel_NOP",
> > +			       hdev->name);
> > +			/* Update cmd_len to include the Intel_NOP command
> > +			 */
> > +			cmd_len += sizeof(*cmd) + cmd->plen;
> > +		}
> > +
> 
> I might have sent you down the wrong patch when looking for the Intel_NOP as next command. After starring at this problem for a bit longer, I think this might be the smarter approach to this.
> 
>         fw_ptr = fw->data + 644;
>         frag_len = 0;
> 
>         while (fw_ptr - fw->data < fw->size) {
>                 struct hci_command_hdr *cmd = (void *)(fw_ptr + frag_len);
> 
>                 frag_len += sizeof(*cmd) + cmd->plen;
> 
>                 /* The paramter length of the secure send command requires
>                  * a 4 byte alignment. It happens so that the firmware file
>                  * contains proper Intel_NOP commands to align the fragments
>                  * as needed.
>                  *
>                  * Send set of commands with 4 byte alignment from the
>                  * firmware data buffer as a single Data fragement.
>                  */
>                 if (!(frag_len % 4)) {
>                         err = btusb_intel_secure_send(hdev, 0x01, frag_len,
>                                                       fw_ptr);
>                         if (err < 0) {
>                                 BT_ERR("%s: Failed to send firmware data (%d)",
>                                        hdev->name, err);
>                                 goto done;
>                         }
> 
>                         fw_ptr += frag_len;
>                         frag_len = 0;
>                 }
>         }
> 
> I know this compiles, but I have not had a chance to actually test it with real hardware. So if this works, then I would prefer to go this route instead. Please give a try and update your patch. Thanks.

I found your RFC and tested with REL182 fw which had alignment issue. Please see my response to that email. Bottom line is that it worked well.

> 
> Regards
> 
> Marcel
>