RE: [PATCH] wifi: mt76: mt7921e: Set memory space enable in PCI_COMMAND if unset

[Limonciello, Mario]

[Public]



> -----Original Message-----
> From: Limonciello, Mario <Mario.Limonciello@xxxxxxx>
> Sent: Friday, March 10, 2023 11:00
> To: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> Cc: Limonciello, Mario <Mario.Limonciello@xxxxxxx>; Tsao, Anson
> <anson.tsao@xxxxxxx>; Felix Fietkau <nbd@xxxxxxxx>; Lorenzo Bianconi
> <lorenzo@xxxxxxxxxx>; Ryder Lee <ryder.lee@xxxxxxxxxxxx>; Shayne Chen
> <shayne.chen@xxxxxxxxxxxx>; Sean Wang <sean.wang@xxxxxxxxxxxx>;
> Kalle Valo <kvalo@xxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>; Eric
> Dumazet <edumazet@xxxxxxxxxx>; Jakub Kicinski <kuba@xxxxxxxxxx>;
> Paolo Abeni <pabeni@xxxxxxxxxx>; linux-wireless@xxxxxxxxxxxxxxx;
> netdev@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> mediatek@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH] wifi: mt76: mt7921e: Set memory space enable in
> PCI_COMMAND if unset
> 
> When the BIOS has been configured for Fast Boot, systems with mt7921e
> have non-functional wifi.  Turning on Fast boot caused both bus master
> enable and memory space enable bits in PCI_COMMAND not to get
> configured.
> 
> The mt7921 driver already sets bus master enable, but explicitly check
> and set memory access enable as well to fix this problem.
> 
> Tested-by: Anson Tsao <anson.tsao@xxxxxxx>
> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> ---
>  drivers/net/wireless/mediatek/mt76/mt7921/pci.c | 6 ++++++
>  1 file changed, 6 insertions(+)

Hi Felix, Lorenzo, Ryder,

Any comments please?

Thanks,

> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> index 8a53d8f286db..24a2aafa6e2a 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c
> @@ -256,6 +256,7 @@ static int mt7921_pci_probe(struct pci_dev *pdev,
>  	struct mt7921_dev *dev;
>  	struct mt76_dev *mdev;
>  	int ret;
> +	u16 cmd;
> 
>  	ret = pcim_enable_device(pdev);
>  	if (ret)
> @@ -265,6 +266,11 @@ static int mt7921_pci_probe(struct pci_dev *pdev,
>  	if (ret)
>  		return ret;
> 
> +	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
> +	if (!(cmd & PCI_COMMAND_MEMORY)) {
> +		cmd |= PCI_COMMAND_MEMORY;
> +		pci_write_config_word(pdev, PCI_COMMAND, cmd);
> +	}
>  	pci_set_master(pdev);
> 
>  	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
> --
> 2.34.1