fix(usb/host): Fix reaction on High-Speed NYET packet

In Scatter-Gather DMA mode, the USB-DWC will automatically enable
PING protocol if an OUT packet is NACKed by the High-Speed device.
The PING bit must be manually reset.

components/hal/esp32p4/include/hal/usb_dwc_ll.h

@@ -790,23 +790,33 @@ static inline void usb_dwc_ll_hctsiz_set_qtd_list_len(volatile usb_dwc_host_chan
     chan->hctsiz_reg.val = hctsiz.val;
 }
 
-static inline void usb_dwc_ll_hctsiz_init(volatile usb_dwc_host_chan_regs_t *chan)
+/**
+ * @brief Perform PING protocol
+ *
+ * PING protocol is automatically enabled if High-Speed device responds with NYET in Scatter-Gather DMA mode.
+ * The application must disable PING for next transfer.
+ * Relevant only for OUT transfers.
+ *
+ * @param[in] chan   Channel registers
+ * @param[in] enable true: Enable PING, false: Disable PING
+ */
+static inline void usb_dwc_ll_hctsiz_set_dopng(volatile usb_dwc_host_chan_regs_t *chan, bool enable)
 {
-    usb_dwc_hctsiz_reg_t hctsiz;
+    chan->hctsiz_reg.dopng = (uint32_t)(enable && !chan->hcchar_reg.epdir);
-    hctsiz.val = chan->hctsiz_reg.val;
-    hctsiz.dopng = 0;         //Don't do ping
-    /*
-    Set SCHED_INFO which occupies xfersize[7:0]
-    It is always set to 0xFF for full speed and not used in Bulk/Ctrl channels
-    */
-    hctsiz.xfersize |= 0xFF;
-    chan->hctsiz_reg.val = hctsiz.val;
 }
 
+/**
+ * @brief Set scheduling info for Periodic channel
+ *
+ * @attention This function must be called for each periodic channel!
+ * @see USB-OTG databook: Table 5-47
+ *
+ * @param[in] chan             Channel registers
+ * @param[in] tokens_per_frame HS: Number of tokens per frame FS: Must be set 8
+ * @param[in] offset           Offset of the channel
+ */
 static inline void usb_dwc_ll_hctsiz_set_sched_info(volatile usb_dwc_host_chan_regs_t *chan, int tokens_per_frame, int offset)
 {
-    // @see USB-OTG databook: Table 5-47
-    // This function is relevant only for HS
     usb_dwc_hctsiz_reg_t hctsiz;
     hctsiz.val = chan->hctsiz_reg.val;
     uint8_t sched_info_val;

components/hal/esp32s2/include/hal/usb_dwc_ll.h

@@ -791,50 +791,33 @@ static inline void usb_dwc_ll_hctsiz_set_qtd_list_len(volatile usb_dwc_host_chan
     chan->hctsiz_reg.val = hctsiz.val;
 }
 
-static inline void usb_dwc_ll_hctsiz_init(volatile usb_dwc_host_chan_regs_t *chan)
+/**
+ * @brief Perform PING protocol
+ *
+ * @note This function is here only for compatibility reasons. PING is not relevant on FS only targets
+ * @param[in] chan   Channel registers
+ * @param[in] enable true: Enable PING, false: Disable PING
+ */
+static inline void usb_dwc_ll_hctsiz_set_dopng(volatile usb_dwc_host_chan_regs_t *chan, bool enable)
 {
-    usb_dwc_hctsiz_reg_t hctsiz;
-    hctsiz.val = chan->hctsiz_reg.val;
-    hctsiz.dopng = 0;         //Don't do ping
-    /*
-    Set SCHED_INFO which occupies xfersize[7:0]
-    It is always set to 0xFF for full speed and not used in Bulk/Ctrl channels
-    */
-    hctsiz.xfersize |= 0xFF;
-    chan->hctsiz_reg.val = hctsiz.val;
 }
 
+/**
+ * @brief Set scheduling info for Periodic channel
+ *
+ * @note ESP32-S2 is Full-Speed only, so SCHED_INFO is always set to 0xFF
+ * @attention This function must be called for each periodic channel!
+ * @see USB-OTG databook: Table 5-47
+ *
+ * @param[in] chan             Channel registers
+ * @param[in] tokens_per_frame Ignored
+ * @param[in] offset           Ignored
+ */
 static inline void usb_dwc_ll_hctsiz_set_sched_info(volatile usb_dwc_host_chan_regs_t *chan, int tokens_per_frame, int offset)
 {
-    // @see USB-OTG databook: Table 5-47
-    // This function is relevant only for HS
     usb_dwc_hctsiz_reg_t hctsiz;
     hctsiz.val = chan->hctsiz_reg.val;
-    uint8_t sched_info_val;
+    hctsiz.xfersize |= 0xFF;
-    switch (tokens_per_frame) {
-        case 1:
-            offset %= 8; // If the required offset > 8, we must wrap around to SCHED_INFO size = 8
-            sched_info_val = 0b00000001;
-            break;
-        case 2:
-            offset %= 4;
-            sched_info_val = 0b00010001;
-            break;
-        case 4:
-            offset %= 2;
-            sched_info_val = 0b01010101;
-            break;
-        case 8:
-            offset = 0;
-            sched_info_val = 0b11111111;
-            break;
-        default:
-            abort();
-            break;
-    }
-    sched_info_val <<= offset;
-    hctsiz.xfersize &= ~(0xFF);
-    hctsiz.xfersize |= sched_info_val;
     chan->hctsiz_reg.val = hctsiz.val;
 }
 

components/hal/esp32s3/include/hal/usb_dwc_ll.h

@@ -791,50 +791,33 @@ static inline void usb_dwc_ll_hctsiz_set_qtd_list_len(volatile usb_dwc_host_chan
     chan->hctsiz_reg.val = hctsiz.val;
 }
 
-static inline void usb_dwc_ll_hctsiz_init(volatile usb_dwc_host_chan_regs_t *chan)
+/**
+ * @brief Perform PING protocol
+ *
+ * @note This function is here only for compatibility reasons. PING is not relevant on FS only targets
+ * @param[in] chan   Channel registers
+ * @param[in] enable true: Enable PING, false: Disable PING
+ */
+static inline void usb_dwc_ll_hctsiz_set_dopng(volatile usb_dwc_host_chan_regs_t *chan, bool enable)
 {
-    usb_dwc_hctsiz_reg_t hctsiz;
-    hctsiz.val = chan->hctsiz_reg.val;
-    hctsiz.dopng = 0;         //Don't do ping
-    /*
-    Set SCHED_INFO which occupies xfersize[7:0]
-    It is always set to 0xFF for full speed and not used in Bulk/Ctrl channels
-    */
-    hctsiz.xfersize |= 0xFF;
-    chan->hctsiz_reg.val = hctsiz.val;
 }
 
+/**
+ * @brief Set scheduling info for Periodic channel
+ *
+ * @note ESP32-S3 is Full-Speed only, so SCHED_INFO is always set to 0xFF
+ * @attention This function must be called for each periodic channel!
+ * @see USB-OTG databook: Table 5-47
+ *
+ * @param[in] chan             Channel registers
+ * @param[in] tokens_per_frame Ignored
+ * @param[in] offset           Ignored
+ */
 static inline void usb_dwc_ll_hctsiz_set_sched_info(volatile usb_dwc_host_chan_regs_t *chan, int tokens_per_frame, int offset)
 {
-    // @see USB-OTG databook: Table 5-47
-    // This function is relevant only for HS
     usb_dwc_hctsiz_reg_t hctsiz;
     hctsiz.val = chan->hctsiz_reg.val;
-    uint8_t sched_info_val;
+    hctsiz.xfersize |= 0xFF;
-    switch (tokens_per_frame) {
-        case 1:
-            offset %= 8; // If the required offset > 8, we must wrap around to SCHED_INFO size = 8
-            sched_info_val = 0b00000001;
-            break;
-        case 2:
-            offset %= 4;
-            sched_info_val = 0b00010001;
-            break;
-        case 4:
-            offset %= 2;
-            sched_info_val = 0b01010101;
-            break;
-        case 8:
-            offset = 0;
-            sched_info_val = 0b11111111;
-            break;
-        default:
-            abort();
-            break;
-    }
-    sched_info_val <<= offset;
-    hctsiz.xfersize &= ~(0xFF);
-    hctsiz.xfersize |= sched_info_val;
     chan->hctsiz_reg.val = hctsiz.val;
 }
 

components/hal/usb_dwc_hal.c

@@ -312,7 +312,6 @@ bool usb_dwc_hal_chan_alloc(usb_dwc_hal_context_t *hal, usb_dwc_hal_chan_t *chan
     usb_dwc_ll_haintmsk_en_chan_intr(hal->dev, 1 << chan_obj->flags.chan_idx);
     usb_dwc_ll_hcintmsk_set_intr_mask(chan_obj->regs, CHAN_INTRS_EN_MSK);  //Unmask interrupts for this channel
     usb_dwc_ll_hctsiz_set_pid(chan_obj->regs, 0);        //Set the initial PID to zero
-    usb_dwc_ll_hctsiz_init(chan_obj->regs);       //Set the non changing parts of the HCTSIZ registers (e.g., do_ping and sched info)
     return true;
 }
 
@@ -383,8 +382,10 @@ void usb_dwc_hal_chan_set_ep_char(usb_dwc_hal_context_t *hal, usb_dwc_hal_chan_t
             hal->periodic_frame_list[index] |= 1 << chan_obj->flags.chan_idx;
         }
         // For HS endpoints we must write to sched_info field of HCTSIZ register to schedule microframes
+        // For FS endpoints sched_info is always 0xFF
+        // LS endpoints do not support periodic transfers
+        unsigned int tokens_per_frame = 0;
         if (ep_char->periodic.is_hs) {
-            unsigned int tokens_per_frame;
             if (ep_char->periodic.interval >= 8) {
                 tokens_per_frame = 1; // 1 token every 8 microframes
             } else if (ep_char->periodic.interval >= 4) {
@@ -394,8 +395,8 @@ void usb_dwc_hal_chan_set_ep_char(usb_dwc_hal_context_t *hal, usb_dwc_hal_chan_t
             } else {
                 tokens_per_frame = 8; // 1 token every microframe
             }
-            usb_dwc_ll_hctsiz_set_sched_info(chan_obj->regs, tokens_per_frame, ep_char->periodic.offset);
         }
+        usb_dwc_ll_hctsiz_set_sched_info(chan_obj->regs, tokens_per_frame, ep_char->periodic.offset);
     }
 }
 
@@ -403,12 +404,14 @@ void usb_dwc_hal_chan_set_ep_char(usb_dwc_hal_context_t *hal, usb_dwc_hal_chan_t
 
 void usb_dwc_hal_chan_activate(usb_dwc_hal_chan_t *chan_obj, void *xfer_desc_list, int desc_list_len, int start_idx)
 {
-    //Cannot activate a channel that has already been enabled or is pending error handling
+    // Cannot activate a channel that has already been enabled or is pending error handling
     HAL_ASSERT(!chan_obj->flags.active);
-    //Set start address of the QTD list and starting QTD index
+    // Make sure that PING is not enabled from previous transaction
+    usb_dwc_ll_hctsiz_set_dopng(chan_obj->regs, false);
+    // Set start address of the QTD list and starting QTD index
     usb_dwc_ll_hcdma_set_qtd_list_addr(chan_obj->regs, xfer_desc_list, start_idx);
     usb_dwc_ll_hctsiz_set_qtd_list_len(chan_obj->regs, desc_list_len);
-    usb_dwc_ll_hcchar_enable_chan(chan_obj->regs); //Start the channel
+    usb_dwc_ll_hcchar_enable_chan(chan_obj->regs); // Start the channel
     chan_obj->flags.active = 1;
 }