> 2015-09-13 23:52 GMT+09:00 Yaniv Gardi <yga...@codeaurora.org>:
>> Optimal values of local UniPro parameters like PA_Hibern8Time &
>> PA_TActivate can help reduce the hibern8 exit latency. If both host and
>> device supports UniPro ver1.6 or later, these parameters will be
>> automatically tuned during link startup itself. But if either host or
>> device doesn't support UniPro ver 1.6 or later, we have to manually
>> tune them. But to keep manual tuning logic simple, we will only do
>> manual tuning if local unipro version doesn't support ver1.6 or later.
>>
>> Signed-off-by: Subhash Jadavani <subha...@codeaurora.org>
>> Signed-off-by: Yaniv Gardi <yga...@codeaurora.org>
>>
>> ---
>> drivers/scsi/ufs/ufshcd.c | 121
>> ++++++++++++++++++++++++++++++++++++++++++++++
>> drivers/scsi/ufs/ufshcd.h | 1 +
>> drivers/scsi/ufs/ufshci.h | 2 +
>> drivers/scsi/ufs/unipro.h | 21 ++++++++
>> 4 files changed, 145 insertions(+)
>>
>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
>> index a8659a9..0938d6c 100644
>> --- a/drivers/scsi/ufs/ufshcd.c
>> +++ b/drivers/scsi/ufs/ufshcd.c
>> @@ -596,6 +596,34 @@ static inline int ufshcd_is_hba_active(struct
>> ufs_hba *hba)
>> return (ufshcd_readl(hba, REG_CONTROLLER_ENABLE) & 0x1) ? 0 : 1;
>> }
>>
>> +u32 ufshcd_get_local_unipro_ver(struct ufs_hba *hba)
>> +{
>> + /* HCI version 1.0 and 1.1 supports UniPro 1.41 */
>> + if ((hba->ufs_version == UFSHCI_VERSION_10) ||
>> + (hba->ufs_version == UFSHCI_VERSION_11))
>> + return UFS_UNIPRO_VER_1_41;
>> + else
>> + return UFS_UNIPRO_VER_1_6;
>> +}
>> +EXPORT_SYMBOL(ufshcd_get_local_unipro_ver);
>> +
>> +static bool ufshcd_is_unipro_pa_params_tuning_req(struct ufs_hba *hba)
>> +{
>> + /*
>> + * If both host and device support UniPro ver1.6 or later, PA
>> layer
>> + * parameters tuning happens during link startup itself.
>> + *
>> + * We can manually tune PA layer parameters if either host or
>> device
>> + * doesn't support UniPro ver 1.6 or later. But to keep manual
>> tuning
>> + * logic simple, we will only do manual tuning if local unipro
>> version
>> + * doesn't support ver1.6 or later.
>> + */
>> + if (ufshcd_get_local_unipro_ver(hba) < UFS_UNIPRO_VER_1_6)
>> + return true;
>> + else
>> + return false;
>> +}
>> +
>> static void ufshcd_ungate_work(struct work_struct *work)
>> {
>> int ret;
>> @@ -4826,6 +4854,98 @@ out:
>> }
>>
>> /**
>> + * ufshcd_tune_pa_tactivate - Tunes PA_TActivate of local UniPro
>> + * @hba: per-adapter instance
>> + *
>> + * PA_TActivate parameter can be tuned manually if UniPro version is
>> less than
>> + * 1.61. PA_TActivate needs to be greater than or equal to peerM-PHY's
>> + * RX_MIN_ACTIVATETIME_CAPABILITY attribute. This optimal value can
>> help reduce
>> + * the hibern8 exit latency.
>> + *
>> + * Returns zero on success, non-zero error value on failure.
>> + */
>> +static int ufshcd_tune_pa_tactivate(struct ufs_hba *hba)
>> +{
>> + int ret = 0;
>> + u32 peer_rx_min_activatetime = 0, tuned_pa_tactivate;
>> +
>> + if (!ufshcd_is_unipro_pa_params_tuning_req(hba))
>> + return 0;
>
> This ufshcd_tune_pa_tactivate() is called only when
> ufshcd_is_unipro_pa_params_tuning_req() returns true. Is this
> second check needed?
>
i could think of having this second check for any future call to
ufshcd_tune_pa_tactivate() which is not protected with a wrapping check
like in this case.
but i guess every call to ufshcd_tune_pa_tactivate()
will use ufshcd_tune_unipro_params() so we are good.
i will remove the 2nd check
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