On 2/24/23 7:46 PM, Kai-Heng Feng wrote:
> Right now r8169 doesn't have parallel access to its config register, but
> the next patch makes the driver access config register at anytime.
>
> So add a spinlock to protect the config register from any potential race.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> ---
> v9:
> - Replace mutex with spinlock so it can be used in softirq context.
>
> v8:
> - Swap the place when using the mutex. Protect when config register is
> unlocked.
>
> v7:
> - This is a new patch.
>
> drivers/net/ethernet/realtek/r8169_main.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index a857650c2e82b..fb73b5386701f 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -613,6 +613,8 @@ struct rtl8169_private {
> struct work_struct work;
> } wk;
>
> + spinlock_t config_lock;
> +
> unsigned supports_gmii:1;
> unsigned aspm_manageable:1;
> dma_addr_t counters_phys_addr;
> @@ -662,10 +664,12 @@ static inline struct device *tp_to_dev(struct rtl8169_private *tp)
> static void rtl_lock_config_regs(struct rtl8169_private *tp)
> {
> RTL_W8(tp, Cfg9346, Cfg9346_Lock);
> + spin_unlock_bh(&tp->config_lock);
You mean spin_lock_bh() here right?
> }
>
> static void rtl_unlock_config_regs(struct rtl8169_private *tp)
> {
> + spin_lock_bh(&tp->config_lock);
> RTL_W8(tp, Cfg9346, Cfg9346_Unlock);
> }
>
> @@ -5217,6 +5221,8 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> return rc;
> }
>
> + spin_lock_init(&tp->config_lock);
> +
> tp->mmio_addr = pcim_iomap_table(pdev)[region];
>
> xid = (RTL_R32(tp, TxConfig) >> 20) & 0xfcf;
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
