On Thu, Apr 05, 2018 at 09:57:20PM +0200, Stefan Fritsch wrote:
> Some em chips have a semaphore ("software flag") to synchronize access
> to certain registers between OS and firmware (ME/AMT).
>
> Make the logic to get the flag match the logic in freebsd. This includes
> higher timeouts and waiting for a previous unlock to complete before
> trying a lock again.
Shouldn't the printfs remain as DEBUGOUT() and DEBUGOUT2() as they are
in FreeBSD?
> ---
> sys/dev/pci/if_em_hw.c | 22 +++++++++++++++++++---
> sys/dev/pci/if_em_hw.h | 2 ++
> 2 files changed, 21 insertions(+), 3 deletions(-)
>
> diff --git sys/dev/pci/if_em_hw.c sys/dev/pci/if_em_hw.c
> index e5084252c29..5bba83cbcd4 100644
> --- sys/dev/pci/if_em_hw.c
> +++ sys/dev/pci/if_em_hw.c
> @@ -9613,9 +9613,21 @@ em_get_software_flag(struct em_hw *hw)
> if (IS_ICH8(hw->mac_type)) {
> while (timeout) {
> extcnf_ctrl = E1000_READ_REG(hw, EXTCNF_CTRL);
> - extcnf_ctrl |= E1000_EXTCNF_CTRL_SWFLAG;
> - E1000_WRITE_REG(hw, EXTCNF_CTRL, extcnf_ctrl);
> + if (!(extcnf_ctrl & E1000_EXTCNF_CTRL_SWFLAG))
> + break;
> + msec_delay_irq(1);
> + timeout--;
> + }
> + if (!timeout) {
> + printf("%s: SW has already locked the resource?\n",
> + __func__);
> + return -E1000_ERR_CONFIG;
> + }
> + timeout = SW_FLAG_TIMEOUT;
> + extcnf_ctrl |= E1000_EXTCNF_CTRL_SWFLAG;
> + E1000_WRITE_REG(hw, EXTCNF_CTRL, extcnf_ctrl);
>
> + while (timeout) {
> extcnf_ctrl = E1000_READ_REG(hw, EXTCNF_CTRL);
> if (extcnf_ctrl & E1000_EXTCNF_CTRL_SWFLAG)
> break;
> @@ -9624,7 +9636,11 @@ em_get_software_flag(struct em_hw *hw)
> }
>
> if (!timeout) {
> - DEBUGOUT("FW or HW locks the resource too long.\n");
> + printf("Failed to acquire the semaphore, FW or HW "
> + "has it: FWSM=0x%8.8x EXTCNF_CTRL=0x%8.8x)\n",
> + E1000_READ_REG(hw, FWSM), extcnf_ctrl);
> + extcnf_ctrl &= ~E1000_EXTCNF_CTRL_SWFLAG;
> + E1000_WRITE_REG(hw, EXTCNF_CTRL, extcnf_ctrl);
> return -E1000_ERR_CONFIG;
> }
> }
> diff --git sys/dev/pci/if_em_hw.h sys/dev/pci/if_em_hw.h
> index 5e415e60a34..71dc91e5582 100644
> --- sys/dev/pci/if_em_hw.h
> +++ sys/dev/pci/if_em_hw.h
> @@ -2755,6 +2755,8 @@ struct em_host_command_info {
> #define AUTO_READ_DONE_TIMEOUT 10
> /* Number of milliseconds we wait for PHY configuration done after MAC reset
> */
> #define PHY_CFG_TIMEOUT 100
> +/* SW Semaphore flag timeout in ms */
> +#define SW_FLAG_TIMEOUT 1000
>
> #define E1000_TX_BUFFER_SIZE ((uint32_t)1514)
>
> --
> 2.13.0
>
