On 10/31/22 12:24, Asutosh Das wrote:
On Thu, Oct 27 2022 at 14:52 -0700, Bart Van Assche wrote:
On 10/20/22 11:03, Asutosh Das wrote:
+u32 ufshcd_mcq_decide_queue_depth(struct ufs_hba *hba)
+{
+ u32 qd, val;
+ int mac;
+
+ mac = ufshcd_mcq_vops_get_hba_mac(hba);
+ if (mac < 0) {
+ val = ufshcd_readl(hba, REG_UFS_MCQ_CFG);
+ mac = FIELD_GET(MCQ_CFG_MAC_MASK, val);
+ }
According to the UFSHCI 4.0 specification the MAC value is set by the
host. Can the above code read the MAC value from the host controller
before it has been set by the host? If so, how about leaving out the
code that reads the MAC value from the controller and making it
mandatory to implement the new get_hba_mac vop?
The reason it is not mandatory to define get_hba_mac vop is UFSHCI 4.0
specification mentions that the default value of MAC is 32. So even if a
vendor
HC doesn't override the MAC, it'd be 32.
Hence, the current code first checks for an override, and if there's
none uses
the default value defined in the HC.
Hi Asutosh,
Please ignore the value reported by the controller in the MAC field of
the MCQConfig register and overwrite the MAC field without reading it
first. It doesn't seem useful to me to read this field. I think the host
should decide about the queue depth no matter what the current value of
the MAC field is.
Thanks,
Bart.
