Re: [PATCH v2 1/3] usb: chipidea: add CI_HDRC_HAS_SHORT_PKT_LIMIT flag

Peter Chen
2024-09-25T12:46:43Z

On 24-09-23 16:12:01, Xu Yang wrote:
> Currently, the imx deivice controller has below limitations:
>
> 1. can't generate short packet interrupt if IOC not set in dTD. So if one
> request span more than one dTDs and only the last dTD set IOC, the usb
> request will pending there if no more data comes.
> 2. the controller can't accurately deliver data to differtent usb requests
> in some cases due to short packet. For example: one usb request span 3
> dTDs, then if the controller received a short packet the next packet
> will go to 2nd dTD of current request rather than the first dTD of next
> request.
> 3. can't build a bus packet use multiple dTDs. For example: controller
> needs to send one packet of 512 bytes use dTD1 (200 bytes) + dTD2
> (312 bytes), actually the host side will see 200 bytes short packet.
>
> Based on these limits, add CI_HDRC_HAS_SHORT_PKT_LIMIT flag and use it on
> imx platforms.
>
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

Acked-by: Peter Chen <peter.chen@kernel.org>
>
> ---
> Changes in v2:
> - new patch
> ---
> drivers/usb/chipidea/ci.h | 1 +
> drivers/usb/chipidea/ci_hdrc_imx.c | 1 +
> drivers/usb/chipidea/core.c | 2 ++
> include/linux/usb/chipidea.h | 1 +
> 4 files changed, 5 insertions(+)
>
> diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
> index 2a38e1eb6546..e4b003d060c2 100644
> --- a/drivers/usb/chipidea/ci.h
> +++ b/drivers/usb/chipidea/ci.h
> @@ -260,6 +260,7 @@ struct ci_hdrc {
> bool b_sess_valid_event;
> bool imx28_write_fix;
> bool has_portsc_pec_bug;
> + bool has_short_pkt_limit;
> bool supports_runtime_pm;
> bool in_lpm;
> bool wakeup_int;
> diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
> index c64ab0e07ea0..17b3ac2ac8a1 100644
> --- a/drivers/usb/chipidea/ci_hdrc_imx.c
> +++ b/drivers/usb/chipidea/ci_hdrc_imx.c
> @@ -342,6 +342,7 @@ static int ci_hdrc_imx_probe(struct platform_device *pdev)
> struct ci_hdrc_platform_data pdata = {
> .name = dev_name(&pdev->dev),
> .capoffset = DEF_CAPOFFSET,
> + .flags = CI_HDRC_HAS_SHORT_PKT_LIMIT,
> .notify_event = ci_hdrc_imx_notify_event,
> };
> int ret;
> diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
> index 835bf2428dc6..5aa16dbfc289 100644
> --- a/drivers/usb/chipidea/core.c
> +++ b/drivers/usb/chipidea/core.c
> @@ -1076,6 +1076,8 @@ static int ci_hdrc_probe(struct platform_device *pdev)
> CI_HDRC_SUPPORTS_RUNTIME_PM);
> ci->has_portsc_pec_bug = !!(ci->platdata->flags &
> CI_HDRC_HAS_PORTSC_PEC_MISSED);
> + ci->has_short_pkt_limit = !!(ci->platdata->flags &
> + CI_HDRC_HAS_SHORT_PKT_LIMIT);
> platform_set_drvdata(pdev, ci);
>
> ret = hw_device_init(ci, base);
> diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
> index 5a7f96684ea2..ebdfef124b2b 100644
> --- a/include/linux/usb/chipidea.h
> +++ b/include/linux/usb/chipidea.h
> @@ -65,6 +65,7 @@ struct ci_hdrc_platform_data {
> #define CI_HDRC_PHY_VBUS_CONTROL BIT(16)
> #define CI_HDRC_HAS_PORTSC_PEC_MISSED BIT(17)
> #define CI_HDRC_FORCE_VBUS_ACTIVE_ALWAYS BIT(18)
> +#define CI_HDRC_HAS_SHORT_PKT_LIMIT BIT(19)
> enum usb_dr_mode dr_mode;
> #define CI_HDRC_CONTROLLER_RESET_EVENT 0
> #define CI_HDRC_CONTROLLER_STOPPED_EVENT 1
> --
> 2.34.1
>