| Message ID | 1592372577-7986-1-git-send-email-macpaul.lin@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v3] usb: gadget: u_serial: improve performance for large data | expand |
Hi, Macpaul Lin <macpaul.lin@mediatek.com> writes: > Nowadays some embedded systems use VCOM to transfer large log and data. > Take LTE MODEM as an example, during the long debugging stage, large > log and data were transfer through VCOM when doing field try or in > operator's lab. Here we suggest slightly increase the transfer buffer > in u_serial.c for performance improving. > > Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com> > --- > Changes for v2: > - Drop previous patch for adding flag which indicates hardware capability in > gadget.h and in DMA engine according to Alan's suggestion. Thanks. > - Replace requested buffer size "REQ_BUF_SIZE" instead of checking hardware > capability. > - Refine commit messages. > Changes for v3: > - Code: no change. > Commit: Add missing change log in v2. > > drivers/usb/gadget/function/u_serial.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c > index 3cfc6e2..d7912a9 100644 > --- a/drivers/usb/gadget/function/u_serial.c > +++ b/drivers/usb/gadget/function/u_serial.c > @@ -80,6 +80,7 @@ > #define QUEUE_SIZE 16 > #define WRITE_BUF_SIZE 8192 /* TX only */ > #define GS_CONSOLE_BUF_SIZE 8192 > +#define REQ_BUF_SIZE 4096 > > /* console info */ > struct gs_console { > @@ -247,7 +248,7 @@ static int gs_start_tx(struct gs_port *port) > break; > > req = list_entry(pool->next, struct usb_request, list); > - len = gs_send_packet(port, req->buf, in->maxpacket); > + len = gs_send_packet(port, req->buf, REQ_BUF_SIZE); > if (len == 0) { > wake_up_interruptible(&port->drain_wait); > break; > @@ -514,7 +515,7 @@ static int gs_alloc_requests(struct usb_ep *ep, struct list_head *head, > * be as speedy as we might otherwise be. > */ > for (i = 0; i < n; i++) { > - req = gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC); > + req = gs_alloc_req(ep, REQ_BUF_SIZE, GFP_ATOMIC); since this can only be applied for the next merge window, it would be much better if you work rework how requests are used here and, as I mentioned in the other subthread, preallocate a list of requests that get recycled. This would allow us to allocate memory without GFP_ATOMIC.
diff --git a/drivers/usb/gadget/function/u_serial.c b/drivers/usb/gadget/function/u_serial.c index 3cfc6e2..d7912a9 100644 --- a/drivers/usb/gadget/function/u_serial.c +++ b/drivers/usb/gadget/function/u_serial.c @@ -80,6 +80,7 @@ #define QUEUE_SIZE 16 #define WRITE_BUF_SIZE 8192 /* TX only */ #define GS_CONSOLE_BUF_SIZE 8192 +#define REQ_BUF_SIZE 4096 /* console info */ struct gs_console { @@ -247,7 +248,7 @@ static int gs_start_tx(struct gs_port *port) break; req = list_entry(pool->next, struct usb_request, list); - len = gs_send_packet(port, req->buf, in->maxpacket); + len = gs_send_packet(port, req->buf, REQ_BUF_SIZE); if (len == 0) { wake_up_interruptible(&port->drain_wait); break; @@ -514,7 +515,7 @@ static int gs_alloc_requests(struct usb_ep *ep, struct list_head *head, * be as speedy as we might otherwise be. */ for (i = 0; i < n; i++) { - req = gs_alloc_req(ep, ep->maxpacket, GFP_ATOMIC); + req = gs_alloc_req(ep, REQ_BUF_SIZE, GFP_ATOMIC); if (!req) return list_empty(head) ? -ENOMEM : 0; req->complete = fn;
Nowadays some embedded systems use VCOM to transfer large log and data. Take LTE MODEM as an example, during the long debugging stage, large log and data were transfer through VCOM when doing field try or in operator's lab. Here we suggest slightly increase the transfer buffer in u_serial.c for performance improving. Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com> --- Changes for v2: - Drop previous patch for adding flag which indicates hardware capability in gadget.h and in DMA engine according to Alan's suggestion. Thanks. - Replace requested buffer size "REQ_BUF_SIZE" instead of checking hardware capability. - Refine commit messages. Changes for v3: - Code: no change. Commit: Add missing change log in v2. drivers/usb/gadget/function/u_serial.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)