Re: [PATCH] clk: qcom: gcc-x1e80100: Keep GCC USB QTB clock always ON

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 3/24/26 3:33 AM, Bjorn Andersson wrote:
> On Mon, Mar 23, 2026 at 10:26:53AM +0530, Jagadeesh Kona wrote:
>>
>>
>> On 3/16/2026 6:26 PM, Dmitry Baryshkov wrote:
>>> On Mon, Mar 16, 2026 at 04:38:21PM +0530, Jagadeesh Kona wrote:
>>>> Keep GCC USB QTB clock always ON which is required for SMMU
>>>> invalidation on X1E80100 platform.
>>>>
>>>> Signed-off-by: Jagadeesh Kona <jagadeesh.kona@oss.qualcomm.com>
>>>> ---
>>>>  drivers/clk/qcom/gcc-x1e80100.c | 1 +
>>>>  1 file changed, 1 insertion(+)
>>>>
>>>> diff --git a/drivers/clk/qcom/gcc-x1e80100.c b/drivers/clk/qcom/gcc-x1e80100.c
>>>> index 74afd12c158c01c121d9aecd56e65c0c302d7cd0..73a2a5112623e5190f41129af7fd76a86603557b 100644
>>>> --- a/drivers/clk/qcom/gcc-x1e80100.c
>>>> +++ b/drivers/clk/qcom/gcc-x1e80100.c
>>>> @@ -7480,6 +7480,7 @@ static int gcc_x1e80100_probe(struct platform_device *pdev)
>>>>  	qcom_branch_set_clk_en(regmap, 0x32004); /* GCC_VIDEO_AHB_CLK */
>>>>  	qcom_branch_set_clk_en(regmap, 0x32030); /* GCC_VIDEO_XO_CLK */
>>>>  	qcom_branch_set_clk_en(regmap, 0x71004); /* GCC_GPU_CFG_AHB_CLK */
>>>> +	qcom_branch_set_clk_en(regmap, 0x7d01c); /* GCC_HLOS1_VOTE_AGGRE_NOC_MMU_USB_QTB_CLK */
>>>
>>> Is it used during all SMMU invalidations or only for those related to
>>> the USB controller?
>>>
>>
>> Yes, it is required for all SMMU invalidations.
> 
> What happens if it's not enabled?

Board goes kaboom if you suspend the system with the flattened USB node
(why only with the flattened one? I would assume that moving the iommus
property makes a difference)

> Why isn't problem described in the
> commit message?

That would be good..
> 
> If it is _required_, wouldn't that imply that this fixes a problem, and
> if so, why isn't there a Fixes: tag?

Certainly

Konrad