Return-Path: MIME-Version: 1.0 In-Reply-To: <1349355967.27233.35.camel@aeonflux> References: <1349335847-1615-1-git-send-email-jesse.sung@canonical.com> <1349335847-1615-2-git-send-email-jesse.sung@canonical.com> <1349344897.27233.13.camel@aeonflux> <1349355967.27233.35.camel@aeonflux> Date: Thu, 4 Oct 2012 21:39:18 +0800 Message-ID: Subject: Re: [PATCH v2 resend 1/2] Introduced a load_firmware callback to struct hci_dev From: Jesse Sung To: Marcel Holtmann Cc: Gustavo Padovan , Johan Hedberg , linux-bluetooth@vger.kernel.org Content-Type: text/plain; charset=UTF-8 List-ID: Hi Marcel, >> >> load_firmware will be called at the end of hci_dev_open() if it >> >> is defined. >> >> >> >> Signed-off-by: Wen-chien Jesse Sung >> >> --- >> >> include/net/bluetooth/hci_core.h | 1 + >> >> net/bluetooth/hci_core.c | 2 ++ >> >> 2 files changed, 3 insertions(+) >> >> >> >> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h >> >> index 593cd1d..40972a3 100644 >> >> --- a/include/net/bluetooth/hci_core.h >> >> +++ b/include/net/bluetooth/hci_core.h >> >> @@ -281,6 +281,7 @@ struct hci_dev { >> >> int (*send)(struct sk_buff *skb); >> >> void (*notify)(struct hci_dev *hdev, unsigned int evt); >> >> int (*ioctl)(struct hci_dev *hdev, unsigned int cmd, unsigned long arg); >> >> + void (*load_firmware)(struct hci_dev *hdev); >> >> }; >> >> >> >> struct hci_conn { >> >> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c >> >> index d4de5db..49be87a 100644 >> >> --- a/net/bluetooth/hci_core.c >> >> +++ b/net/bluetooth/hci_core.c >> >> @@ -725,6 +725,8 @@ int hci_dev_open(__u16 dev) >> >> done: >> >> hci_req_unlock(hdev); >> >> hci_dev_put(hdev); >> >> + if (!ret && hdev->load_firmware) >> >> + hdev->load_firmware(hdev); >> >> return ret; >> >> } >> >> >> > >> > has anybody thought this through actually? Do we need to reload the >> > firmware after every HCI_Reset? Since hci_dev_open() is used at least >> > twice during normal operation. And for every RFKILL or power down/up >> > cycle of the chip. >> > >> > And there is an internal process of hci_dev_open() trigger on >> > registration and others triggered by hciconfig hci0 up. I am pretty much >> > against having to wait for all this firmware loading crap during every >> > bring up of the device. Especially since it always does a trip via >> > request_firmware(). >> >> In the second patch, firmware loading would be done only once per >> power cycle of the chip. Since I think it should be the device driver, not hci, >> who knows when and how to load firmware, the lock is placed in btusb.c. > > and how does the driver knows these details? That makes no sense. How > does the driver know it got rebooted? > > The hci_dev_open() will start the transport. And as I explained before, > that can happen twice during boot time. Please take a look at the second part of this patchset, which is in patch 2/2. Loading firmware is needed when the chip is rebooted, and a reboot would trigger a probe in btusb. So btusb can know a firmware loading is needed whenever a new patchram device is probed. And the load_firmware callback in btusb would do test_and_set_bit to ensure that the loading process would only be done once. Thanks, Jesse