RE: [PATCH 1/1] usb: cdns3: fix super speed mass storage gadget device failure at imx8qm

[Pawel Laszczak]

>>The mass storage gadget has one IN and one OUT endpoint. The below
>>(Fixes) commit aimed to utilize all hardware FIFO to support composited
>>gadget devices. This resulted in an ep_buf_size of 15 when a single
>>gadget was enabled, such as the mass storage gadget.
>>
>>However, it was found that there are unknown limitations on the imx8qm
>>and imx8qxp B0 platforms. The device would fail to work if ep_buf_size
>>exceeded 9.
>>
>>To resolve this issue, this patch reverts to the old settings used
>>before the below commit for the imx8qm and imx8qxp B0 platforms.
>>
>>Fixes: dce49449e04f ("usb: cdns3: allocate TX FIFO size according to
>>composite EP number")
>>
>>Signed-off-by: Frank Li <Frank.Li@xxxxxxx>
>>---
>>
>>I hope cdns engineer, such as pawell@xxxxxxxxxxx help identfy the root
>>cause.
>>Look like old version ip use more memory then what ep_cfg show.
>>
>> drivers/usb/cdns3/cdns3-gadget.c | 11 +++++++++++
>> 1 file changed, 11 insertions(+)
>>
>>diff --git a/drivers/usb/cdns3/cdns3-gadget.c
>>b/drivers/usb/cdns3/cdns3- gadget.c index 5adcb349718c..497c8e87dabf
>>100644
>>--- a/drivers/usb/cdns3/cdns3-gadget.c
>>+++ b/drivers/usb/cdns3/cdns3-gadget.c
>>@@ -3005,6 +3005,17 @@ static int cdns3_gadget_check_config(struct
>>usb_gadget *gadget)
>> 	priv_dev->ep_buf_size = priv_dev->ep_iso_burst =
>> 			(priv_dev->onchip_buffers - 2) / (n_in + 1);
>>
>>+	/*
>>+	 * There are unknown hardware limition: when work at super speed
>>mode,
>>+	 * ep_buffer_size can't bigger than 9 for one IN and OUT case at
>>i.MX8QM
>>+	 * and i.MX8QXP B0, which report there are 32k memory.
>>+	 * Rollback to original settings for the these chipes.
>>+	 */
>>+	if (priv_dev->dev_ver < DEV_VER_V2) {
>>+		priv_dev->ep_buf_size = min_t(u8, priv_dev->ep_buf_size, 4);
>>+		priv_dev->ep_iso_burst = min_t(u8, priv_dev->ep_iso_burst,
>>3);
>>+	}
>>+
>> 	return 0;
>> }
>
>I'm not sure whether you have 32KB. I remember that you had a Soc which
>have only 18KB on-chip memory and value in usb_cap2 was incorrect.
>It was the reason why the on-chip-buff-size property has been added to
>driver.
>
>Please confirm that you have 32KB, then I will recreate such test on my testing
>board.
>

I've made the MSC test with the following endpoint configuration;
[ 6732.999537] cdns-usb3 cdns-usb3.1: Configure ep1in: with val 74000e05
[ 6732.999565] cdns-usb3 cdns-usb3.1: Configure ep1out: with val 74000e15

So, I used the 14 buffers per endpoint and run bonnie++ as tester.
I didn't find any issue.  

Regards,
Pawel
>>
>>--
>>2.34.1