Messages in this thread Patch in this message | | | Date | Wed, 17 Nov 2010 11:04:59 +0530 | Subject | Re: [PATCH v5] Bluetooth: btwilink driver | From | Pavan Savoy <> |
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Gustavo,
On Wed, Nov 17, 2010 at 4:24 AM, Gustavo F. Padovan <padovan@profusion.mobi> wrote: > Hi Pavan, > > * pavan_savoy@ti.com <pavan_savoy@ti.com> [2010-11-10 08:07:26 -0500]: > >> From: Pavan Savoy <pavan_savoy@ti.com> >> >> Marcel, >> >> Thanks for the comments... >> This patch contains, >> v5 comments :- >> declaration and assiging of variables and private data fixed up. >> proper casting. >> removed redundant un-necessary checks in send_frame. >> HCI_RUNNING fixes in terms of test_and_set/clear bit instead of set and >> clear. >> removed redundant checks for hdev, skb being NULL. >> removed module_param of reset, also WiLink don't need HCI_RESET anyways. >> removed ti_st_register_dev function and functionality moved to _probe. >> module_init/exit function names fixed up. >> >> stat byte counter increments and tx_complete is similar to hci_ldisc. >> Also I have not implemented the flush routine, since the functionality >> which needs to be done in flush routine is done in the underlying driver >> which is the shared transport driver and moreover the btwilink driver by >> itself doesn't maintains queue or data relevant to transport, so nothing >> to do. >> >> And Yes, I have verified this driver with multiple up/down reset on >> hci0. >> Also I generally test a2dp/ftp to verify large data transfers. > > Before re-submit a patch you have to fix all issues reported by the > reviewer or reply to patch thread why do you think you right and don't > want to change that. That is not happening with your patches, you are > not fixing all the stuff before re-submiting and it is not the first > time. If you do it right we can review it fast and your code goes > earlier to mainline. > You should also answer the questions first like "Where is the > ti_st_proto.write coming from?" You just ignored the > review and submitted a new patch.
This is the reason, I tend to keep the patch comments in the mail. I have mentioned here the 1. comments I have taken care of, 2. few comments which I don't understand why it is like that and which are not taken care of.
Also the question on ti_st_proto.write, I have answered it twice in mail, once to you and once to marcel, for more clarity I have even added it in the code comments, Please have a look @ line >> + /* ti_st_proto.write is filled up by the underlying shared >> + * transport driver upon registration >> + */ As to why this function is not EXPORT_SYMBOL and just an function pointer, Yes I had it as function pointer - But since something like _read is callback from the protocol driver perspective - to maintain uniformity I have this as function pointer. (Note: comments to other drivers which are based on ST driver intended read/write to be pointers which register/unregister to be EXPORTs).
Ok, apart from this there was an open question as why I am checking for only 2 error conditions, it is because the underlying driver only can send those 2 errors and nothing else (st_register has few errors it can throw...)
I understand my problem with test_and_set_bit, I will correct it, But I still feel I do nothing critical before test/set so as to return error if already opened - But will correct it and do it at the beginning ...
Also what should I be doing regarding the deferred stats update? I checked up hci_ldisc which is what this code is pretty much based on, and see that it does pretty much the same thing .... hci_uart_tx_complete is called after the tty->ops->write correct ?
I also now understand the issue in module_init regarding the platform_driver registration and will fix that.
Thanks, Pavan >> >> v4 comments :- >> module init now returns what platform_driver_register returns. >> type casting of void* private data has been removed >> >> v3 comments :- >> Lizardo, >> I have taken care of most of the comments you had. >> Have re-wrote some of the code commenting you've mentioned. >> Thanks for the comments, >> >> The other few like -EPERM for platform driver registration is to keep >> it similar to other drivers, type casting is maintained just to feel safe >> and have style similar to other drivers. >> BT_WILINK in Kconfig is similar to BT_MRVL. >> I hope those aren't too critical. >> >> -- patch description -- >> >> This is the bluetooth protocol driver for the TI WiLink7 chipsets. >> Texas Instrument's WiLink chipsets combine wireless technologies >> like BT, FM, GPS and WLAN onto a single chip. >> >> This Bluetooth driver works on top of the TI_ST shared transport >> line discipline driver which also allows other drivers like >> FM V4L2 and GPS character driver to make use of the same UART interface. >> >> Kconfig and Makefile modifications to enable the Bluetooth >> driver for Texas Instrument's WiLink 7 chipset. >> >> Signed-off-by: Pavan Savoy <pavan_savoy@ti.com> >> --- >> drivers/bluetooth/Kconfig | 10 + >> drivers/bluetooth/Makefile | 1 + >> drivers/bluetooth/btwilink.c | 379 ++++++++++++++++++++++++++++++++++++++++++ >> 3 files changed, 390 insertions(+), 0 deletions(-) >> create mode 100644 drivers/bluetooth/btwilink.c >> >> diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig >> index 02deef4..8e0de9a 100644 >> --- a/drivers/bluetooth/Kconfig >> +++ b/drivers/bluetooth/Kconfig >> @@ -219,4 +219,14 @@ config BT_ATH3K >> Say Y here to compile support for "Atheros firmware download driver" >> into the kernel or say M to compile it as module (ath3k). >> >> +config BT_WILINK >> + tristate "Texas Instruments WiLink7 driver" >> + depends on TI_ST >> + help >> + This enables the Bluetooth driver for Texas Instrument's BT/FM/GPS >> + combo devices. This makes use of shared transport line discipline >> + core driver to communicate with the BT core of the combo chip. >> + >> + Say Y here to compile support for Texas Instrument's WiLink7 driver >> + into the kernel or say M to compile it as module. >> endmenu >> diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile >> index 71bdf13..f4460f4 100644 >> --- a/drivers/bluetooth/Makefile >> +++ b/drivers/bluetooth/Makefile >> @@ -18,6 +18,7 @@ obj-$(CONFIG_BT_HCIBTSDIO) += btsdio.o >> obj-$(CONFIG_BT_ATH3K) += ath3k.o >> obj-$(CONFIG_BT_MRVL) += btmrvl.o >> obj-$(CONFIG_BT_MRVL_SDIO) += btmrvl_sdio.o >> +obj-$(CONFIG_BT_WILINK) += btwilink.o >> >> btmrvl-y := btmrvl_main.o >> btmrvl-$(CONFIG_DEBUG_FS) += btmrvl_debugfs.o >> diff --git a/drivers/bluetooth/btwilink.c b/drivers/bluetooth/btwilink.c >> new file mode 100644 >> index 0000000..1b1c4bc >> --- /dev/null >> +++ b/drivers/bluetooth/btwilink.c >> @@ -0,0 +1,379 @@ >> +/* >> + * Texas Instrument's Bluetooth Driver For Shared Transport. >> + * >> + * Bluetooth Driver acts as interface between HCI core and >> + * TI Shared Transport Layer. >> + * >> + * Copyright (C) 2009-2010 Texas Instruments >> + * Author: Raja Mani <raja_mani@ti.com> >> + * Pavan Savoy <pavan_savoy@ti.com> >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + * >> + * This program is distributed in the hope that it will be useful, >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> + * GNU General Public License for more details. >> + * >> + * You should have received a copy of the GNU General Public License >> + * along with this program; if not, write to the Free Software >> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA >> + * >> + */ >> + >> +#include <linux/platform_device.h> >> +#include <net/bluetooth/bluetooth.h> >> +#include <net/bluetooth/hci_core.h> >> + >> +#include <linux/ti_wilink_st.h> >> + >> +/* Bluetooth Driver Version */ >> +#define VERSION "1.0" >> + >> +/* Number of seconds to wait for registration completion >> + * when ST returns PENDING status. >> + */ >> +#define BT_REGISTER_TIMEOUT 6000 /* 6 sec */ >> + >> +/** >> + * struct ti_st - driver operation structure >> + * @hdev: hci device pointer which binds to bt driver >> + * @reg_status: ST registration callback status >> + * @st_write: write function provided by the ST driver >> + * to be used by the driver during send_frame. >> + * @wait_reg_completion - completion sync between ti_st_open >> + * and ti_st_registration_completion_cb. >> + */ >> +struct ti_st { >> + struct hci_dev *hdev; >> + char reg_status; >> + long (*st_write) (struct sk_buff *); >> + struct completion wait_reg_completion; >> +}; >> + >> +/* Increments HCI counters based on pocket ID (cmd,acl,sco) */ >> +static inline void ti_st_tx_complete(struct ti_st *hst, int pkt_type) >> +{ >> + struct hci_dev *hdev = hst->hdev; >> + >> + /* Update HCI stat counters */ >> + switch (pkt_type) { >> + case HCI_COMMAND_PKT: >> + hdev->stat.cmd_tx++; >> + break; >> + >> + case HCI_ACLDATA_PKT: >> + hdev->stat.acl_tx++; >> + break; >> + >> + case HCI_SCODATA_PKT: >> + hdev->stat.sco_tx++; >> + break; >> + } >> +} >> + >> +/* ------- Interfaces to Shared Transport ------ */ >> + >> +/* Called by ST layer to indicate protocol registration completion >> + * status.ti_st_open() function will wait for signal from this >> + * API when st_register() function returns ST_PENDING. >> + */ >> +static void st_registration_completion_cb(void *priv_data, char data) >> +{ >> + struct ti_st *lhst = priv_data; >> + >> + /* Save registration status for use in ti_st_open() */ >> + lhst->reg_status = data; >> + /* complete the wait in ti_st_open() */ >> + complete(&lhst->wait_reg_completion); >> +} >> + >> +/* Called by Shared Transport layer when receive data is >> + * available */ >> +static long st_receive(void *priv_data, struct sk_buff *skb) >> +{ >> + struct ti_st *lhst = priv_data; >> + int err; >> + >> + if (!skb) >> + return -EFAULT; >> + >> + if (!lhst) { >> + kfree_skb(skb); >> + return -EFAULT; >> + } >> + >> + skb->dev = (void *) lhst->hdev; >> + >> + /* Forward skb to HCI core layer */ >> + err = hci_recv_frame(skb); >> + if (err < 0) { >> + BT_ERR("Unable to push skb to HCI core(%d)", err); >> + return err; >> + } >> + >> + lhst->hdev->stat.byte_rx += skb->len; >> + >> + return 0; >> +} >> + >> +/* ------- Interfaces to HCI layer ------ */ >> +/* protocol structure registered with shared transport */ >> +static struct st_proto_s ti_st_proto = { >> + .type = ST_BT, >> + .recv = st_receive, >> + .reg_complete_cb = st_registration_completion_cb, >> +}; >> + >> +/* Called from HCI core to initialize the device */ >> +static int ti_st_open(struct hci_dev *hdev) >> +{ >> + unsigned long timeleft; >> + struct ti_st *hst; >> + int err; >> + >> + BT_DBG("%s %p", hdev->name, hdev); >> + >> + /* provide contexts for callbacks from ST */ >> + hst = hdev->driver_data; >> + ti_st_proto.priv_data = hst; >> + >> + err = st_register(&ti_st_proto); >> + if (err == -EINPROGRESS) { >> + /* Prepare wait-for-completion handler data structures. >> + * Needed to synchronize this and >> + * st_registration_completion_cb() functions. >> + */ >> + init_completion(&hst->wait_reg_completion); >> + >> + /* Reset ST registration callback status flag , this value >> + * will be updated in ti_st_registration_completion_cb() >> + * function whenever it called from ST driver. >> + */ >> + hst->reg_status = -EINPROGRESS; >> + >> + /* ST is busy with either protocol registration or firmware >> + * download. Wait until the registration callback is called >> + */ >> + BT_DBG(" waiting for registration completion signal from ST"); >> + >> + timeleft = wait_for_completion_timeout >> + (&hst->wait_reg_completion, >> + msecs_to_jiffies(BT_REGISTER_TIMEOUT)); >> + if (!timeleft) { >> + BT_ERR("Timeout(%d sec),didn't get reg " >> + "completion signal from ST", >> + BT_REGISTER_TIMEOUT / 1000); >> + return -ETIMEDOUT; >> + } >> + >> + /* Is ST registration callback called with ERROR status? */ >> + if (hst->reg_status != 0) { >> + BT_ERR("ST registration completed with invalid " >> + "status %d", hst->reg_status); >> + return -EAGAIN; >> + } >> + err = 0; >> + } else if (err == -EPERM) { >> + BT_ERR("st_register failed %d", err); >> + return err; >> + } > > Again, you are checking for only EPERM and EINPROGRESS. You should check > for everything. I actually don't undertand why you have a special check > for EPERM. > >> + >> + /* ti_st_proto.write is filled up by the underlying shared >> + * transport driver upon registration >> + */ >> + hst->st_write = ti_st_proto.write; > > I do not like that, the underlying should export the write function. > >> + if (!hst->st_write) { >> + BT_ERR("undefined ST write function"); >> + >> + /* Undo registration with ST */ >> + err = st_unregister(ST_BT); >> + if (err) >> + BT_ERR("st_unregister() failed with error %d", err); >> + >> + hst->st_write = NULL; >> + return err; >> + } >> + >> + /* Registration with ST layer is successful, >> + * hardware is ready to accept commands from HCI core. >> + */ >> + if (test_and_set_bit(HCI_RUNNING, &hdev->flags)) { >> + clear_bit(HCI_RUNNING, &hdev->flags); >> + err = st_unregister(ST_BT); >> + if (err) >> + BT_ERR("st_unregister() failed with error %d", err); >> + hst->st_write = NULL; >> + } > > > What are you trying to do here? test_and_set_bit() result doesn't say > nothing about error and you shall put test_and_set_bit should be in the > beginning, to know if your device is already opened or not and then > clear_bit if some error ocurrs during the function. > >> + >> + return err; >> +} >> + >> +/* Close device */ >> +static int ti_st_close(struct hci_dev *hdev) >> +{ >> + int err; >> + struct ti_st *hst = hdev->driver_data; >> + >> + /* continue to unregister from transport */ >> + err = st_unregister(ST_BT); >> + if (err) >> + BT_ERR("st_unregister() failed with error %d", err); >> + >> + hst->st_write = NULL; >> + >> + if (!test_and_clear_bit(HCI_RUNNING, &hdev->flags)) >> + return 0; > > test_and_clear_bit should come first to check if your device is already > closed. > >> + >> + return err; >> +} >> + >> +static int ti_st_send_frame(struct sk_buff *skb) >> +{ >> + struct hci_dev *hdev; >> + struct ti_st *hst; >> + long len; >> + >> + hdev = (struct hci_dev *)skb->dev; >> + >> + if (!test_bit(HCI_RUNNING, &hdev->flags)) >> + return -EBUSY; >> + >> + hst = hdev->driver_data; >> + >> + /* Prepend skb with frame type */ >> + memcpy(skb_push(skb, 1), &bt_cb(skb)->pkt_type, 1); >> + >> + BT_DBG(" %s: type %d len %d", hdev->name, bt_cb(skb)->pkt_type, >> + skb->len); >> + >> + /* Insert skb to shared transport layer's transmit queue. >> + * Freeing skb memory is taken care in shared transport layer, >> + * so don't free skb memory here. >> + */ >> + len = hst->st_write(skb); >> + if (len < 0) { >> + kfree_skb(skb); >> + BT_ERR(" ST write failed (%ld)", len); >> + return -EAGAIN; > > Why EAGAIN? > >> + } >> + >> + /* ST accepted our skb. So, Go ahead and do rest */ >> + hdev->stat.byte_tx += len; >> + ti_st_tx_complete(hst, bt_cb(skb)->pkt_type); > > From Marcel in the other thread: > "What is the reason for this deferred stats update. That code looks > pretty much hackish to me." > >> + >> + return 0; >> +} >> + >> +static void ti_st_destruct(struct hci_dev *hdev) >> +{ >> + BT_DBG("%s", hdev->name); >> + >> + /* free ti_st memory */ > > get ride of the comment, it's pointless > >> + kfree(hdev->driver_data); >> + >> + return; > > No return; here > >> +} >> + >> +static int bt_ti_probe(struct platform_device *pdev) >> +{ >> + static struct ti_st *hst; >> + struct hci_dev *hdev; >> + int err; >> + >> + hst = kzalloc(sizeof(struct ti_st), GFP_KERNEL); >> + if (!hst) >> + return -ENOMEM; >> + >> + /* Expose "hciX" device to user space */ >> + hdev = hci_alloc_dev(); >> + if (!hdev) >> + return -ENOMEM; > > You are leaking hst, if hci_alloc_dev() fails. > >> + >> + BT_DBG("hdev %p", hdev); >> + >> + hst->hdev = hdev; >> + hdev->bus = HCI_UART; >> + hdev->driver_data = hst; >> + hdev->open = ti_st_open; >> + hdev->close = ti_st_close; >> + hdev->flush = NULL; >> + hdev->send = ti_st_send_frame; >> + hdev->destruct = ti_st_destruct; >> + hdev->owner = THIS_MODULE; >> + >> + err = hci_register_dev(hdev); >> + if (err < 0) { >> + BT_ERR("Can't register HCI device error %d", err); >> + hci_free_dev(hdev); >> + return err; >> + } >> + >> + BT_DBG(" HCI device registered (hdev %p)", hdev); >> + >> + dev_set_drvdata(&pdev->dev, hst); >> + return err; >> +} >> + >> +static int bt_ti_remove(struct platform_device *pdev) >> +{ >> + struct hci_dev *hdev; >> + struct ti_st *hst = dev_get_drvdata(&pdev->dev); >> + >> + if (!hst) >> + return -EFAULT; >> + >> + hdev = hst->hdev; >> + ti_st_close(hdev); >> + hci_unregister_dev(hdev); >> + >> + /* Free HCI device memory */ >> + hci_free_dev(hdev); >> + >> + /* Free driver data memory */ > > get ride of both commnets here. The name of the funcion is already > saying that. > >> + kfree(hst); >> + >> + dev_set_drvdata(&pdev->dev, NULL); >> + return 0; >> +} >> + >> +static struct platform_driver btwilink_driver = { >> + .probe = bt_ti_probe, >> + .remove = bt_ti_remove, >> + .driver = { >> + .name = "btwilink", >> + .owner = THIS_MODULE, >> + }, >> +}; >> + >> +/* ------- Module Init/Exit interfaces ------ */ >> +static int __init btwilink_init(void) >> +{ >> + long ret; >> + >> + BT_INFO(" Bluetooth Driver for TI WiLink - Version %s", VERSION); >> + >> + ret = platform_driver_register(&btwilink_driver); >> + if (ret != 0) { >> + BT_ERR("btwilink platform driver registration failed"); >> + return ret; >> + } >> + return 0; > > Old issue again: > > From Marcel: please just do like we do with all other drivers; > > BT_INFO(...) > > return platform_driver_register(&btwilink_driver); > > -- > Gustavo F. Padovan > http://profusion.mobi > -- > To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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