On 1/24/2025 1:35 PM, Manivannan Sadhasivam wrote:
On Tue, Jan 21, 2025 at 11:52:42AM +0800, Ziqi Chen wrote:
On 1/20/2025 11:41 PM, Manivannan Sadhasivam wrote:
On Mon, Jan 20, 2025 at 08:07:07PM +0800, Ziqi Chen wrote:
Hi Mani，
Thanks for your comments~
On 1/19/2025 3:30 PM, Manivannan Sadhasivam wrote:
On Thu, Jan 16, 2025 at 05:11:45PM +0800, Ziqi Chen wrote:
From: Can Guo <quic_cang@xxxxxxxxxxx>
Implement the freq_to_gear_speed() vops to map the unipro core clock
frequency to the corresponding maximum supported gear speed.
Co-developed-by: Ziqi Chen <quic_ziqichen@xxxxxxxxxxx>
Signed-off-by: Ziqi Chen <quic_ziqichen@xxxxxxxxxxx>
Signed-off-by: Can Guo <quic_cang@xxxxxxxxxxx>
---
drivers/ufs/host/ufs-qcom.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 1e8a23eb8c13..64263fa884f5 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -1803,6 +1803,37 @@ static int ufs_qcom_config_esi(struct ufs_hba *hba)
return ret;
}
+static int ufs_qcom_freq_to_gear_speed(struct ufs_hba *hba, unsigned long freq, u32 *gear)
+{
+ int ret = 0 >
Please do not initialize ret with 0. Return the actual value directly.
If we don't initialize ret here, for the cases of freq matched in the table,
it will return an unknown ret value. It is not make sense, right?
Or you may want to say we don't need “ret” , just need to return gear value?
But we need this "ret" to check whether the freq is invalid.
I meant to say that you can just return 0 directly in success case and -EINVAL
in the case of error.
Hi Mani,
If we don't print freq here , I think your suggestion is very good. If we
print freq in this function , using "ret" to indicate success case and
failure case and print freq an the end of this function is the way to avoid
code bloat.
How do you think about it?
I don't understand how code bloat comes into picture here. I'm just asking for
this:
static int ufs_qcom_freq_to_gear_speed(struct ufs_hba *hba, unsigned long freq, u32 *gear)
{
switch (freq) {
case 403000000:
*gear = UFS_HS_G5;
break;
...
default:
dev_err(hba->dev, "Unsupported clock freq: %ld\n", freq);
return -EINVAL;
}
return 0;
}
+
+ switch (freq) {
+ case 403000000:
+ *gear = UFS_HS_G5;
+ break;
+ case 300000000:
+ *gear = UFS_HS_G4;
+ break;
+ case 201500000:
+ *gear = UFS_HS_G3;
+ break;
+ case 150000000:
+ case 100000000:
+ *gear = UFS_HS_G2;
+ break;
+ case 75000000:
+ case 37500000:
+ *gear = UFS_HS_G1;
+ break;
+ default:
+ ret = -EINVAL;
+ dev_err(hba->dev, "Unsupported clock freq\n");
Print the freq.
Ok, thank for your suggestion, we can print freq with dev_dbg() in next
version.
No, use dev_err() with the freq. >
- Mani
I think use dev_err() here does not make sense:
1. This print is not an error message , just an information print. Using
dev_err() reduces the readability of this code.
Then why it was dev_err() in the first place?
2. This prints will be print very frequent, I afraid it will increase the
latency of clock scaling.
First you need to decide whether this print should warn user or not. It is
telling users that the OPP table supplied a frequency that doesn't match the
gear speed. This can happen if there is a discrepancy between DT and the driver.
In that case, the users *should* be warned to fix the driver/DT. If you bury it
with dev_dbg(), no one will notice it.
If your concern is with the frequency of logs, then use dev_err_ratelimited().
- Mani
I misunderstand your point Mani, I thought you want me to print freq for
all cases... if you mean that print failure case, I already added it in
patch V2.
-Ziqi
