On 1/15/25 6:02 PM, DooHyun Hwang(황두현/Device S/W Solution Lab.(MX)/삼성전자)
wrote:
I want to keep sending NOP_OUT commands repeatedly to get a response
from the UFS device, as per the existing method. To accommodate this method,
I propose increasing the total timeout duration by increasing the single timeout
value(defined by NOP_OUT_TIMEOUT) from 50ms to 100ms rather than
increasing the timeout value(defined by NOP_OUT_TIMEOUT) from 50ms to 1000ms
or increasing the retry count value(defined by NOP_OUT_RETRIES).
This is time measurement log confirmed on a real device with NOP_OUT_TIMEOUT is 100ms
1. normal operation
[ 2.010156] [6: kworker/u18:0: 76] ufshcd-qcom 1d84000.ufshc: [TEST] ufshcd_verify_dev_init: takes 1271 us, retries = 1 * 100ms.
2. issued log : exceeds 500ms
[ 2.524525] [6: kworker/u17:2: 141] ufshcd-qcom 1d84000.ufshc: [TEST] ufshcd_verify_dev_init: takes 533000 us, retries = 6 * 100ms.
And a certain UFS vendor has confirmed that the response to NOP_OUT command
can be delayed by up to 540ms in certain circumstances on a specific model.
Thank you for having provided all this additional information. Because
of the above clarification, feel free to add:
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
