Re: [PATCH v2] PCI: vmd: Fix spinlock usage on config access for RT kernel

From: Ryo Takakura
Date: Wed Dec 18 2024 - 19:55:58 EST


Hi Keith,

On Wed, 18 Dec 2024 08:36:54 -0700, Keith Busch wrote:
>> @@ -385,13 +384,11 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
>> {
>> struct vmd_dev *vmd = vmd_from_bus(bus);
>> void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
>> - unsigned long flags;
>> int ret = 0;
>>
>> if (!addr)
>> return -EFAULT;
>>
>> - spin_lock_irqsave(&vmd->cfg_lock, flags);
>> switch (len) {
>> case 1:
>> *value = readb(addr);
>
>There's a comment above this function explaining the need for the lock,
>which doesn't make a lot of sense after this patch.

Thanks for pointing it out! It slipped my mind.
I'll leave it as it is for the next patch :)

Sincerely,
Ryo Takakura