[RESEND] [PATCH 3/3] iwlwifi: Load firmware exclusively for Intel WiFi

[RESEND] [PATCH 3/3] iwlwifi: Load firmware exclusively for Intel WiFi

[Kai-Heng Feng]

To avoid the firmware loading race between Bluetooth and WiFi on Intel
8260, load firmware exclusively when BT_INTEL is enabled.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 .../net/wireless/intel/iwlwifi/pcie/trans.c   | 39 ++++++++++++++++++-
 1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
index cc8c53dc0ab6..bbd7e199e968 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/trans.c
@@ -72,6 +72,10 @@
 #include <linux/pm_runtime.h>
 #include <linux/module.h>
 
+#if IS_ENABLED(CONFIG_BT_INTEL)
+#include <linux/intel-wifi-bt.h>
+#endif
+
 #include "iwl-drv.h"
 #include "iwl-trans.h"
 #include "iwl-csr.h"
@@ -1335,6 +1339,10 @@ static int iwl_trans_pcie_start_fw(struct iwl_trans *trans,
 	bool hw_rfkill;
 	int ret;
 
+#if IS_ENABLED(CONFIG_BT_INTEL)
+	void (*firmware_lock_func)(void);
+	void (*firmware_unlock_func)(void);
+#endif
 	/* This may fail if AMT took ownership of the device */
 	if (iwl_pcie_prepare_card_hw(trans)) {
 		IWL_WARN(trans, "Exit HW not ready\n");
@@ -1401,8 +1409,37 @@ static int iwl_trans_pcie_start_fw(struct iwl_trans *trans,
 	iwl_write32(trans, CSR_UCODE_DRV_GP1_CLR, CSR_UCODE_SW_BIT_RFKILL);
 
 	/* Load the given image to the HW */
-	if (trans->cfg->device_family >= IWL_DEVICE_FAMILY_8000)
+	if (trans->cfg->device_family >= IWL_DEVICE_FAMILY_8000) {
+#if IS_ENABLED(CONFIG_BT_INTEL)
+		firmware_lock_func = symbol_request(btintel_firmware_lock);
+		firmware_unlock_func = symbol_request(btintel_firmware_unlock);
+		if (!firmware_lock_func || !firmware_unlock_func) {
+			if (firmware_lock_func) {
+				symbol_put(btintel_firmware_lock);
+				firmware_lock_func = NULL;
+			}
+
+			if (firmware_unlock_func) {
+				symbol_put(btintel_firmware_unlock);
+				firmware_unlock_func = NULL;
+			}
+		}
+
+		if (firmware_lock_func)
+			firmware_lock_func();
+#endif
 		ret = iwl_pcie_load_given_ucode_8000(trans, fw);
+
+#if IS_ENABLED(CONFIG_BT_INTEL)
+		if (firmware_unlock_func) {
+			firmware_unlock_func();
+			symbol_put(btintel_firmware_lock);
+			firmware_lock_func = NULL;
+			symbol_put(btintel_firmware_unlock);
+			firmware_unlock_func = NULL;
+		}
+#endif
+	}
 	else
 		ret = iwl_pcie_load_given_ucode(trans, fw);
 
-- 
2.17.1

Re: [RESEND] [PATCH 3/3] iwlwifi: Load firmware exclusively for Intel WiFi

[Kalle Valo]

Kai-Heng Feng <kai.heng.feng@canonical.com> writes:

> To avoid the firmware loading race between Bluetooth and WiFi on Intel
> 8260, load firmware exclusively when BT_INTEL is enabled.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>

Still the commit log tells nothing about the actual problem which makes
review impossible.

-- 
Kalle Valo

Re: [RESEND] [PATCH 3/3] iwlwifi: Load firmware exclusively for Intel WiFi

[Kai Heng Feng]

> On Oct 3, 2018, at 5:10 PM, Kalle Valo <kvalo-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org> wrote:
> 
> Kai-Heng Feng <kai.heng.feng-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> writes:
> 
>> To avoid the firmware loading race between Bluetooth and WiFi on Intel
>> 8260, load firmware exclusively when BT_INTEL is enabled.
>> 
>> Signed-off-by: Kai-Heng Feng <kai.heng.feng-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
> 
> Still the commit log tells nothing about the actual problem which makes
> review impossible.

Sorry for that. The first two patches [1] only sends to linux-bluetooth and LMKL.

I don’t know what really happened at hardware/firmware level, but making btusb and iwlwifi load firmware sequentially can workaround the issue.

Matt Chen may be able to explain this issue with more detail.

[1] https://lkml.org/lkml/2018/10/3/322

> 
> -- 
> Kalle Valo

Re: [RESEND] [PATCH 3/3] iwlwifi: Load firmware exclusively for Intel WiFi

[Kalle Valo]

Kai Heng Feng <kai.heng.feng@canonical.com> writes:

>> On Oct 3, 2018, at 5:10 PM, Kalle Valo <kvalo@codeaurora.org> wrote:
>> 
>> Kai-Heng Feng <kai.heng.feng@canonical.com> writes:
>> 
>>> To avoid the firmware loading race between Bluetooth and WiFi on Intel
>>> 8260, load firmware exclusively when BT_INTEL is enabled.
>>> 
>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>> 
>> Still the commit log tells nothing about the actual problem which makes
>> review impossible.
>
> Sorry for that. The first two patches [1] only sends to linux-bluetooth and LMKL.

For a patchset like this you should CC linux-wireless for all patches,
otherwise people just get confused. And even more so as patch 3 seems to
depend on the other patches.

> I don’t know what really happened at hardware/firmware level, but
> making btusb and iwlwifi load firmware sequentially can workaround the
> issue.

We don't apply ugly workarounds without understanding the issue.

> Matt Chen may be able to explain this issue with more detail.

Then you need to work with Matt so that the issue is properly explained
in the commit log.

-- 
Kalle Valo

Re: [RESEND] [PATCH 3/3] iwlwifi: Load firmware exclusively for Intel WiFi

[Kalle Valo]

Kalle Valo <kvalo@codeaurora.org> writes:

> Kai Heng Feng <kai.heng.feng@canonical.com> writes:
>
>>> On Oct 3, 2018, at 5:10 PM, Kalle Valo <kvalo@codeaurora.org> wrote:
>>> 
>>> Kai-Heng Feng <kai.heng.feng@canonical.com> writes:
>>> 
>>>> To avoid the firmware loading race between Bluetooth and WiFi on Intel
>>>> 8260, load firmware exclusively when BT_INTEL is enabled.
>>>> 
>>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>>> 
>>> Still the commit log tells nothing about the actual problem which makes
>>> review impossible.
>>
>> Sorry for that. The first two patches [1] only sends to linux-bluetooth and LMKL.
>
> For a patchset like this you should CC linux-wireless for all patches,
> otherwise people just get confused. And even more so as patch 3 seems to
> depend on the other patches.
>
>> I don’t know what really happened at hardware/firmware level, but
>> making btusb and iwlwifi load firmware sequentially can workaround the
>> issue.
>
> We don't apply ugly workarounds without understanding the issue.
>
>> Matt Chen may be able to explain this issue with more detail.
>
> Then you need to work with Matt so that the issue is properly explained
> in the commit log.

linux-bluetooth was not CCed, adding that.

-- 
Kalle Valo

RE: [RESEND] [PATCH 3/3] iwlwifi: Load firmware exclusively for Intel WiFi

[Grumbach, Emmanuel]

> 
> > On Oct 3, 2018, at 5:10 PM, Kalle Valo <kvalo@codeaurora.org> wrote:
> >
> > Kai-Heng Feng <kai.heng.feng@canonical.com> writes:
> >
> >> To avoid the firmware loading race between Bluetooth and WiFi on
> >> Intel 8260, load firmware exclusively when BT_INTEL is enabled.
> >>
> >> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
> >
> > Still the commit log tells nothing about the actual problem which
> > makes review impossible.
> 
> Sorry for that. The first two patches [1] only sends to linux-bluetooth and
> LMKL.
> 
> I don’t know what really happened at hardware/firmware level, but making
> btusb and iwlwifi load firmware sequentially can workaround the issue.
> 
> Matt Chen may be able to explain this issue with more detail.
> 
> [1] https://lkml.org/lkml/2018/10/3/322
>

I just read the code of this patch and I don't quite understand.
You have a function that is declared as a non-inline function in two different header files?
btintel_firmware_lock is declared here:

--- /dev/null
+++ b/include/linux/intel-wifi-bt.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __INTEL_WIFI_BT_H__
+#define __INTEL_WIFI_BT_H__
+
+void btintel_firmware_lock(void);

And ...

diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h
index 41c642cc523f..1373ffc2b575 100644
--- a/drivers/bluetooth/btintel.h
+++ b/drivers/bluetooth/btintel.h
@@ -102,6 +102,8 @@ int btintel_read_boot_params(struct hci_dev *hdev,
 			     struct intel_boot_params *params);
 int btintel_download_firmware(struct hci_dev *dev, const struct firmware *fw,
 			      u32 *boot_param);
+void btintel_firmware_lock(void);


This can't be right.

Re: [RESEND] [PATCH 3/3] iwlwifi: Load firmware exclusively for Intel WiFi

[Kalle Valo]

+ linux-bluetooth

"Grumbach, Emmanuel" <emmanuel.grumbach@intel.com> writes:

>> 
>> > On Oct 3, 2018, at 5:10 PM, Kalle Valo <kvalo@codeaurora.org> wrote:
>> >
>> > Kai-Heng Feng <kai.heng.feng@canonical.com> writes:
>> >
>> >> To avoid the firmware loading race between Bluetooth and WiFi on
>> >> Intel 8260, load firmware exclusively when BT_INTEL is enabled.
>> >>
>> >> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
>> >
>> > Still the commit log tells nothing about the actual problem which
>> > makes review impossible.
>> 
>> Sorry for that. The first two patches [1] only sends to linux-bluetooth and
>> LMKL.
>> 
>> I don’t know what really happened at hardware/firmware level, but making
>> btusb and iwlwifi load firmware sequentially can workaround the issue.
>> 
>> Matt Chen may be able to explain this issue with more detail.
>> 
>> [1] https://lkml.org/lkml/2018/10/3/322
>>
>
> I just read the code of this patch and I don't quite understand.
> You have a function that is declared as a non-inline function in two different header files?
> btintel_firmware_lock is declared here:
>
> --- /dev/null
> +++ b/include/linux/intel-wifi-bt.h
> @@ -0,0 +1,8 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __INTEL_WIFI_BT_H__
> +#define __INTEL_WIFI_BT_H__
> +
> +void btintel_firmware_lock(void);
>
> And ...
>
> diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h
> index 41c642cc523f..1373ffc2b575 100644
> --- a/drivers/bluetooth/btintel.h
> +++ b/drivers/bluetooth/btintel.h
> @@ -102,6 +102,8 @@ int btintel_read_boot_params(struct hci_dev *hdev,
>  			     struct intel_boot_params *params);
>  int btintel_download_firmware(struct hci_dev *dev, const struct firmware *fw,
>  			      u32 *boot_param);
> +void btintel_firmware_lock(void);
>
>
> This can't be right.

-- 
Kalle Valo