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Subject: Re: [PATCH v3] bluetooth: hci_bcm: enable IRQ capability from node
From:   Marcel Holtmann <marcel@holtmann.org>
In-Reply-To: <cf77eec5df92b1845f0bf7cc8eb53edd4af9e1bf.camel@suse.de>
Date:   Thu, 12 Dec 2019 21:46:32 +0100
Cc:     Guillaume La Roque <glaroque@baylibre.com>,
        Johan Hedberg <johan.hedberg@gmail.com>,
        BlueZ <linux-bluetooth@vger.kernel.org>,
        lkml <linux-kernel@vger.kernel.org>, khilman@baylibre.com,
        linux-rpi-kernel <linux-rpi-kernel@lists.infradead.org>
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Message-Id: <0CF02341-CF69-4680-B61F-DC5C0702F1A2@holtmann.org>
References: <20191211094923.20220-1-glaroque@baylibre.com>
 <cf77eec5df92b1845f0bf7cc8eb53edd4af9e1bf.camel@suse.de>
To:     Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Sender: linux-bluetooth-owner@vger.kernel.org
Precedence: bulk

Hi Nicolas,

>> Actually IRQ can be found from GPIO but all platforms don't support
>> gpiod_to_irq, it's the case on amlogic chip.
>> so to have possibility to use interrupt mode we need to add interrupts
>> field in node and support it in driver.
>> 
>> Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
>> ---
>> drivers/bluetooth/hci_bcm.c | 3 +++
>> 1 file changed, 3 insertions(+)
> 
> This triggers the following panic on Raspberry Pi 4:
> 
> [    6.634507] Unable to handle kernel NULL pointer dereference at virtual
> address 0000000000000018
> [    6.643486] Mem abort info:
> [    6.646350]   ESR = 0x96000004
> [    6.649466]   EC = 0x25: DABT (current EL), IL = 32 bits
> [    6.654873]   SET = 0, FnV = 0
> [    6.657977]   EA = 0, S1PTW = 0
> [    6.661201] Data abort info:
> [    6.664135]   ISV = 0, ISS = 0x00000004
> [    6.668042]   CM = 0, WnR = 0
> [    6.671061] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000f3c83000
> [    6.677627] [0000000000000018] pgd=0000000000000000
> [    6.682595] Internal error: Oops: 96000004 [#1] PREEMPT SMP
> [    6.688255] Modules linked in: hci_uart brcmutil btqca btbcm cfg80211
> bluetooth raspberrypi_cpufreq ecdh_generic ecc rfkill clk_raspberrypi
> raspberrypi_hwmon pwm_bcm2835 crct10dif_ce bcm2835_dma i2c_bcm2835 pcie_brcmstb
> ip_tables x_tables ipv6 nf_defrag_ipv6
> [    6.711519] CPU: 3 PID: 39 Comm: kworker/u8:1 Not tainted 5.5.0-rc1-next-
> 20191212-00009-geb500fec1e34-dirty #26
> [    6.721771] Hardware name: Raspberry Pi 4 Model B Rev 1.1 (DT)
> [    6.727709] Workqueue: events_unbound async_run_entry_fn
> [    6.733105] pstate: a0000005 (NzCv daif -PAN -UAO)
> [    6.737971] pc : platform_get_irq_optional+0xa4/0x260
> [    6.743099] lr : platform_get_irq_optional+0x6c/0x260
> [    6.748226] sp : ffff8000101b3c20
> [    6.751586] x29: ffff8000101b3c20 x28: ffffd4bd4a957000
> [    6.756980] x27: ffff0000f6c0c070 x26: ffff0000f6c0c020
> [    6.762373] x25: 0000000000000000 x24: 0000000000000000
> [    6.767767] x23: ffff0000f6238c00 x22: ffffd4bd4a241a38
> [    6.773159] x21: ffffd4bd49e95838 x20: ffff0000f6238bf0
> [    6.778552] x19: 0000000000000000 x18: 0000000000000010
> [    6.783944] x17: 0000000000000000 x16: ffffd4bd497117a8
> [    6.789337] x15: ffff0000f6fc0470 x14: 0720072007200720
> [    6.794730] x13: 0720072007200720 x12: 0720072007200720
> [    6.800123] x11: 0720072007200720 x10: 0720072007200720
> [    6.805516] x9 : 0720072007200720 x8 : 0720072007200720
> [    6.810913] x7 : ffffd4bd496ad210 x6 : 000000000000017d
> [    6.810922] x5 : 0000000000000000 x4 : ffff0000fb7fa1b0
> [    6.821713] x3 : 00000000f6238800 x2 : 0000000000000000
> [    6.821716] x1 : 0000000000000000 x0 : 0000000000000000
> [    6.821720] Call trace:
> [    6.821730]  platform_get_irq_optional+0xa4/0x260
> [    6.839768]  platform_get_irq+0x1c/0x58
> [    6.839792]  bcm_serdev_probe+0x40/0x138 [hci_uart]
> [    6.839805]  serdev_drv_probe+0x34/0x70
> [    6.852544]  really_probe+0xd8/0x428
> [    6.852546]  driver_probe_device+0xdc/0x130
> [    6.852549]  __driver_attach_async_helper+0xa8/0xb0
> [    6.852558]  async_run_entry_fn+0x40/0x1a0
> [    6.869534]  process_one_work+0x19c/0x320
> [    6.869537]  worker_thread+0x48/0x420
> [    6.877319]  kthread+0xf0/0x120
> [    6.877324]  ret_from_fork+0x10/0x18
> [    6.877330] Code: 17ffffef f9419293 937a7c02 8b020273 (f9400e62)
> [    6.890329] ---[ end trace 3ebb39e57973e0b7 ]---
> 
>> 
>> diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c
>> index f8f5c593a05c..9f52d57c56de 100644
>> --- a/drivers/bluetooth/hci_bcm.c
>> +++ b/drivers/bluetooth/hci_bcm.c
>> @@ -1409,6 +1409,7 @@ static int bcm_serdev_probe(struct serdev_device
>> *serdev)
>> {
>> 	struct bcm_device *bcmdev;
>> 	const struct bcm_device_data *data;
>> +	struct platform_device *pdev;
>> 	int err;
>> 
>> 	bcmdev = devm_kzalloc(&serdev->dev, sizeof(*bcmdev), GFP_KERNEL);
>> @@ -1421,6 +1422,8 @@ static int bcm_serdev_probe(struct serdev_device
>> *serdev)
>> #endif
>> 	bcmdev->serdev_hu.serdev = serdev;
>> 	serdev_device_set_drvdata(serdev, bcmdev);
>> +	pdev = to_platform_device(bcmdev->dev);
> 
> Ultimately bcmdev->dev here comes from a serdev device not a platform device,
> right?

I was afraid of this, but then nobody spoke up. Can we fix this or should I just revert the patch?

Regards

Marcel