Re: [PATCH Internal] thunderbolt: Remove enabling/disabling TMU based on CLx

[Mika Westerberg <mika.westerberg@linux.intel.com>]

On Thu, Jul 06, 2023 at 07:18:38PM +0530, Sanjay R Mehta wrote:
> > Agree. we will have to see what is going wrong in this case.
> 
> Hi Mika,

Hi,

> When an unplug event occurs, the TMU is disabled by configuring the
> TSPacketInterval bits in TMU_RTR_CS_3 to 0 using the
> tb_switch_tmu_rate_write() API, followed by disabling the Time
> Synchronization Handshake using the DTS bit in TMU_ADP_CS_6. The code
> snippet for this functionality is present in the tb_switch_tmu_disable()
> function, as shown below:
> 
> ```
> tb_switch_tmu_rate_write(sw, TB_SWITCH_TMU_RATE_OFF);
> tb_port_tmu_time_sync_disable(up);
> ret = tb_port_tmu_time_sync_disable(down);
> if (ret)
>     return ret;
> ```
> 
> However, we have observed that the tb_switch_tmu_rate_write() function
> fails to disable the TMU rate, and the code proceeds with disabling the
> Time Synchronization Handshake. To address this issue, we have modified
> the code to check the return value of the tb_switch_tmu_rate_write()
> function and only proceed with disabling the Time Synchronization
> Handshake if the TMU rate disabling succeeds. The updated code is as
> follows:
> 
> ```
> ret = tb_switch_tmu_rate_write(sw, tmu_rates[TB_SWITCH_TMU_MODE_OFF]);
> if (ret)
>     return ret;
> tb_port_tmu_time_sync_disable(up);
> ret = tb_port_tmu_time_sync_disable(down);
> if (ret)
>     return ret;
> ```
> 
> Please let us know your thoughts on this solution.

Makes sense to me.