[PATCH v5 06/10] phy: qcom: Add M31 based eUSB2 PHY driver

[Konrad Dybcio]

On 5/22/25 12:56 PM, Song Xue wrote:
> 
> 
> On 4/22/2025 6:00 AM, Melody Olvera wrote:
>> From: Wesley Cheng <quic_wcheng at quicinc.com>
>>
>> SM8750 utilizes an eUSB2 PHY from M31.  Add the initialization
>> sequences to bring it out of reset and into an operational state.  This
>> differs to the M31 USB driver, in that the M31 eUSB2 driver will
>> require a connection to an eUSB2 repeater.  This PHY driver will handle
>> the initialization of the associated eUSB2 repeater when required.
>>
>> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov at oss.qualcomm.com>
>> Signed-off-by: Wesley Cheng <quic_wcheng at quicinc.com>
>> Signed-off-by: Melody Olvera <melody.olvera at oss.qualcomm.com>
>> ---

[...]

>> +static int m31eusb2_phy_write_readback(void __iomem *base, u32 offset,
>> +                    const u32 mask, u32 val)
>> +{
>> +    u32 write_val;
>> +    u32 tmp;
>> +
>> +    tmp = readl_relaxed(base + offset);
>> +    tmp &= ~mask;
>> +    write_val = tmp | val;
>> +
>> +    writel_relaxed(write_val, base + offset);
>> +
>> +    tmp = readl_relaxed(base + offset);
> is it better to use "readl" which can guarantee write visibility?

let's use non-relaxed to save the meaningless discussion from dragging
on, in fight for what is literally a couple nanoseconds each boot

Konrad