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

Xu Yang
2024-09-23T08:11:07Z

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>

---
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