[PATCH 4.19 059/276] usb: dwc2: gadget: Increase descriptors count for ISOCs

From: Greg Kroah-Hartman
Date: Wed May 29 2019 - 23:25:23 EST


[ Upstream commit 54f37f56631747075f1f9a2f0edf6ba405e3e66c ]

Some function drivers queueing more than 128 ISOC requests at a time.
To avoid "descriptor chain full" cases, increasing descriptors count
from MAX_DMA_DESC_NUM_GENERIC to MAX_DMA_DESC_NUM_HS_ISOC for ISOC's
only.

Signed-off-by: Minas Harutyunyan <hminas@xxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/dwc2/gadget.c | 27 +++++++++++++++------------
1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 220c0f9b89b0b..03614ef64ca47 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -675,13 +675,11 @@ static unsigned int dwc2_gadget_get_chain_limit(struct dwc2_hsotg_ep *hs_ep)
unsigned int maxsize;

if (is_isoc)
- maxsize = hs_ep->dir_in ? DEV_DMA_ISOC_TX_NBYTES_LIMIT :
- DEV_DMA_ISOC_RX_NBYTES_LIMIT;
+ maxsize = (hs_ep->dir_in ? DEV_DMA_ISOC_TX_NBYTES_LIMIT :
+ DEV_DMA_ISOC_RX_NBYTES_LIMIT) *
+ MAX_DMA_DESC_NUM_HS_ISOC;
else
- maxsize = DEV_DMA_NBYTES_LIMIT;
-
- /* Above size of one descriptor was chosen, multiple it */
- maxsize *= MAX_DMA_DESC_NUM_GENERIC;
+ maxsize = DEV_DMA_NBYTES_LIMIT * MAX_DMA_DESC_NUM_GENERIC;

return maxsize;
}
@@ -864,7 +862,7 @@ static int dwc2_gadget_fill_isoc_desc(struct dwc2_hsotg_ep *hs_ep,

/* Update index of last configured entry in the chain */
hs_ep->next_desc++;
- if (hs_ep->next_desc >= MAX_DMA_DESC_NUM_GENERIC)
+ if (hs_ep->next_desc >= MAX_DMA_DESC_NUM_HS_ISOC)
hs_ep->next_desc = 0;

return 0;
@@ -896,7 +894,7 @@ static void dwc2_gadget_start_isoc_ddma(struct dwc2_hsotg_ep *hs_ep)
}

/* Initialize descriptor chain by Host Busy status */
- for (i = 0; i < MAX_DMA_DESC_NUM_GENERIC; i++) {
+ for (i = 0; i < MAX_DMA_DESC_NUM_HS_ISOC; i++) {
desc = &hs_ep->desc_list[i];
desc->status = 0;
desc->status |= (DEV_DMA_BUFF_STS_HBUSY
@@ -2083,7 +2081,7 @@ static void dwc2_gadget_complete_isoc_request_ddma(struct dwc2_hsotg_ep *hs_ep)
dwc2_hsotg_complete_request(hsotg, hs_ep, hs_req, 0);

hs_ep->compl_desc++;
- if (hs_ep->compl_desc > (MAX_DMA_DESC_NUM_GENERIC - 1))
+ if (hs_ep->compl_desc > (MAX_DMA_DESC_NUM_HS_ISOC - 1))
hs_ep->compl_desc = 0;
desc_sts = hs_ep->desc_list[hs_ep->compl_desc].status;
}
@@ -3779,6 +3777,7 @@ static int dwc2_hsotg_ep_enable(struct usb_ep *ep,
unsigned int i, val, size;
int ret = 0;
unsigned char ep_type;
+ int desc_num;

dev_dbg(hsotg->dev,
"%s: ep %s: a 0x%02x, attr 0x%02x, mps 0x%04x, intr %d\n",
@@ -3825,11 +3824,15 @@ static int dwc2_hsotg_ep_enable(struct usb_ep *ep,
dev_dbg(hsotg->dev, "%s: read DxEPCTL=0x%08x from 0x%08x\n",
__func__, epctrl, epctrl_reg);

+ if (using_desc_dma(hsotg) && ep_type == USB_ENDPOINT_XFER_ISOC)
+ desc_num = MAX_DMA_DESC_NUM_HS_ISOC;
+ else
+ desc_num = MAX_DMA_DESC_NUM_GENERIC;
+
/* Allocate DMA descriptor chain for non-ctrl endpoints */
if (using_desc_dma(hsotg) && !hs_ep->desc_list) {
hs_ep->desc_list = dmam_alloc_coherent(hsotg->dev,
- MAX_DMA_DESC_NUM_GENERIC *
- sizeof(struct dwc2_dma_desc),
+ desc_num * sizeof(struct dwc2_dma_desc),
&hs_ep->desc_list_dma, GFP_ATOMIC);
if (!hs_ep->desc_list) {
ret = -ENOMEM;
@@ -3971,7 +3974,7 @@ static int dwc2_hsotg_ep_enable(struct usb_ep *ep,

error2:
if (ret && using_desc_dma(hsotg) && hs_ep->desc_list) {
- dmam_free_coherent(hsotg->dev, MAX_DMA_DESC_NUM_GENERIC *
+ dmam_free_coherent(hsotg->dev, desc_num *
sizeof(struct dwc2_dma_desc),
hs_ep->desc_list, hs_ep->desc_list_dma);
hs_ep->desc_list = NULL;
--
2.20.1