Re: [PATCH v3 4/9] Bluetooth: btrtl: add support for the RTL8723BS and RTL8723DS chips

[Hans de Goede <hdegoede@xxxxxxxxxx>]

HI,

On 14-07-18 18:09, Marcel Holtmann wrote:
> Hi Hans,
>
> > The Realtek RTL8723BS and RTL8723DS chipsets are SDIO wifi chips. They
> > also contain a Bluetooth module which is connected via UART to the host.
> >
> > Realtek's userspace initialization tool (rtk_hciattach) differentiates
> > these two via the HCI version and revision returned by the
> > HCI_OP_READ_LOCAL_VERSION command.
> > Additionally we apply these checks only the for UART devices. Everything
> > else is assumed to be a "RTL8723B" which was originally supported by the
> > driver (communicating via USB).
> >
> > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> > Signed-off-by: Jeremy Cline <jeremy@xxxxxxxxxx>
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> > ---
> > Changes in v2 (Hans de Goede)
> > -Fix some minor style issues / checkpatch warnings
> > ---
> > drivers/bluetooth/btrtl.c | 51 ++++++++++++++++++++++++++++++++++++---
> > 1 file changed, 47 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/bluetooth/btrtl.c b/drivers/bluetooth/btrtl.c
> > index 6c0d88d23d6d..8dacca64fe41 100644
> > --- a/drivers/bluetooth/btrtl.c
> > +++ b/drivers/bluetooth/btrtl.c
> > @@ -38,6 +38,8 @@
> >
> > #define IC_MATCH_FL_LMPSUBV	(1 << 0)
> > #define IC_MATCH_FL_HCIREV	(1 << 1)
> > +#define IC_MATCH_FL_HCIVER	(1 << 2)
> > +#define IC_MATCH_FL_HCIBUS	(1 << 3)
> > #define IC_INFO(lmps, hcir) \
> > 	.match_flags = IC_MATCH_FL_LMPSUBV | IC_MATCH_FL_HCIREV, \
> > 	.lmp_subver = (lmps), \
> > @@ -47,6 +49,8 @@ struct id_table {
> > 	__u16 match_flags;
> > 	__u16 lmp_subver;
> > 	__u16 hci_rev;
> > +	__u8 hci_ver;
> > +	__u8 hci_bus;
> > 	bool config_needed;
> > 	bool has_rom_version;
> > 	char *fw_name;
> > @@ -75,6 +79,18 @@ static const struct id_table ic_id_table[] = {
> > 	  .fw_name = "rtl_bt/rtl8723a_fw.bin",
> > 	  .cfg_name = NULL },
> >
> > +	/* 8723BS */
> > +	{ .match_flags = IC_MATCH_FL_LMPSUBV | IC_MATCH_FL_HCIREV |
> > +			 IC_MATCH_FL_HCIVER | IC_MATCH_FL_HCIBUS,
> > +	  .lmp_subver = RTL_ROM_LMP_8723B,
> > +	  .hci_rev = 0xb,
> > +	  .hci_ver = 6,
> > +	  .hci_bus = HCI_UART,
> > +	  .config_needed = true,
> > +	  .has_rom_version = true,
> > +	  .fw_name  = "rtl_bt/rtl8723bs_fw.bin",
> > +	  .cfg_name = "rtl_bt/rtl8723bs_config.bin" },
> > +
> > 	/* 8723B */
> > 	{ IC_INFO(RTL_ROM_LMP_8723B, 0xb),
> > 	  .config_needed = false,
> > @@ -89,6 +105,18 @@ static const struct id_table ic_id_table[] = {
> > 	  .fw_name  = "rtl_bt/rtl8723d_fw.bin",
> > 	  .cfg_name = "rtl_bt/rtl8723d_config.bin" },
> >
> > +	/* 8723DS */
> > +	{ .match_flags = IC_MATCH_FL_LMPSUBV | IC_MATCH_FL_HCIREV |
> > +			 IC_MATCH_FL_HCIVER | IC_MATCH_FL_HCIBUS,
> > +	  .lmp_subver = RTL_ROM_LMP_8723B,
> > +	  .hci_rev = 0xd,
> > +	  .hci_ver = 8,
> > +	  .hci_bus = HCI_UART,
> > +	  .config_needed = true,
> > +	  .has_rom_version = true,
> > +	  .fw_name  = "rtl_bt/rtl8723ds_fw.bin",
> > +	  .cfg_name = "rtl_bt/rtl8723ds_config.bin" },
> > +
> > 	/* 8821A */
> > 	{ IC_INFO(RTL_ROM_LMP_8821A, 0xa),
> > 	  .config_needed = false,
> > @@ -118,7 +146,8 @@ static const struct id_table ic_id_table[] = {
> > 	  .cfg_name = "rtl_bt/rtl8822b_config.bin" },
> > 	};
> >
> > -static const struct id_table *btrtl_match_ic(u16 lmp_subver, u16 hci_rev)
> > +static const struct id_table *btrtl_match_ic(u16 lmp_subver, u16 hci_rev,
> > +					     u8 hci_ver, u8 hci_bus)
> > {
> > 	int i;
> >
> > @@ -129,6 +158,12 @@ static const struct id_table *btrtl_match_ic(u16 lmp_subver, u16 hci_rev)
> > 		if ((ic_id_table[i].match_flags & IC_MATCH_FL_HCIREV) &&
> > 		    (ic_id_table[i].hci_rev != hci_rev))
> > 			continue;
> > +		if ((ic_id_table[i].match_flags & IC_MATCH_FL_HCIVER) &&
> > +		    (ic_id_table[i].hci_ver != hci_ver))
> > +			continue;
> > +		if ((ic_id_table[i].match_flags & IC_MATCH_FL_HCIBUS) &&
> > +		    (ic_id_table[i].hci_bus != hci_bus))
> > +			continue;
> >
> > 		break;
> > 	}
> > @@ -481,6 +516,7 @@ struct btrtl_device_info *btrtl_initialize(struct hci_dev *hdev)
> > 	struct sk_buff *skb;
> > 	struct hci_rp_read_local_version *resp;
> > 	u16 hci_rev, lmp_subver;
> > +	u8 hci_ver;
> > 	int ret;
> >
> > 	btrtl_dev = kzalloc(sizeof(*btrtl_dev), GFP_KERNEL);
> > @@ -501,14 +537,17 @@ struct btrtl_device_info *btrtl_initialize(struct hci_dev *hdev)
> > 		    resp->hci_ver, resp->hci_rev,
> > 		    resp->lmp_ver, resp->lmp_subver);
> >
> > +	hci_ver = resp->hci_ver;
> > 	hci_rev = le16_to_cpu(resp->hci_rev);
> > 	lmp_subver = le16_to_cpu(resp->lmp_subver);
> > 	kfree_skb(skb);
> >
> > -	btrtl_dev->ic_info = btrtl_match_ic(lmp_subver, hci_rev);
> > +	btrtl_dev->ic_info = btrtl_match_ic(lmp_subver, hci_rev, hci_ver,
> > +					    hdev->bus);
> > +
>
> I am bit reluctant to let you use hdev->bus here since that should be essentially local to the core. I know you set it before calling hci_register_dev, but it was never really designed to be accessed again by the driver? Do you need access to it or can this be done internally in the driver?

hdev->bus is only used to differentiate between the USB 8723B and the SDIO 8723BS
devices when looking up the info in the ic_id_table[]. As such all that is done
is a "hdev->bus == HCI_UART" comparison, which seems innocent enough and not
prone to breakage if the core changes its use of bus a bit.

The alternative would be to pass the bus-type from the USB / UART specific
probe() functions as parameter to the various intermediate functions until
we end up in btrtl_initialize() but that seems a but silly since we have
it available in hdev->bus already.

Regards,

Hans
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html