[U-Boot] [PATCH V2 1/2] usb: dwc2: fix aligned buffer usage

[U-Boot] [PATCH V2 1/2] usb: dwc2: fix aligned buffer usage

[Stephen Warren]

The original aligned_buffer usage:
a) Uselessly copied data into the aligned buffer even for IN
   transactions. Fix this my making the copy conditional.
b) Always programmed the HW to transfer to/from the start of the aligned
   buffer. This worked fine for OUT transactions since the memcpy copied
   the OUT data to this location too. However, for large IN transactions,
   since the copy from the aligned buffer to the "client" buffer was
   deferred until after all chunks were transferred. it resulted in each
   chunk's transfer over-writing the data for the first transfer. Fix
   this by copying IN data as soon as it's received.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
---
v2: Move all memcpy()s back into the per-chunk loop; we can't rely on
maxpacket being a multiple of 8-bytes, so we need to copy each chunk to
the aligned_buffer not aligned_buffer+done; the HW requires 8-byte
alignment for the DMA buffer.

 drivers/usb/host/dwc2.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index 5a1c44a8fb75..05d21b7948f5 100644
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -795,7 +795,9 @@ int chunk_msg(struct usb_device *dev, unsigned long pipe, int *pid, int in,
 		       (*pid << DWC2_HCTSIZ_PID_OFFSET),
 		       &hc_regs->hctsiz);
 
-		memcpy(aligned_buffer, (char *)buffer + done, len - done);
+		if (!in)
+			memcpy(aligned_buffer, (char *)buffer + done, len);
+
 		writel((uint32_t)aligned_buffer, &hc_regs->hcdma);
 
 		/* Set host channel enable after all other setup is complete. */
@@ -810,16 +812,16 @@ int chunk_msg(struct usb_device *dev, unsigned long pipe, int *pid, int in,
 			break;
 		}
 
-		done += xfer_len;
 		if (in) {
-			done -= sub;
+			xfer_len -= sub;
+			memcpy(buffer + done, aligned_buffer, xfer_len);
 			if (sub)
 				stop_transfer = 1;
 		}
-	} while ((done < len) && !stop_transfer);
 
-	if (done && in)
-		memcpy(buffer, aligned_buffer, done);
+		done += xfer_len;
+
+	} while ((done < len) && !stop_transfer);
 
 	writel(0, &hc_regs->hcintmsk);
 	writel(0xFFFFFFFF, &hc_regs->hcint);
-- 
1.9.1

[U-Boot] [PATCH V2 2/2] usb: dwc2: remove restriction on buffer length

[Stephen Warren]

Each USB transfer is split up into chunks that are held in an aligned
buffer. This imposes a limit on the size of each chunk, but no limit on
the total size of transferred data. Fix the logic in chunk_msg() not to
reject large transfers, but simply take the size of the aligned buffer
into account when calculating the chunk size.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
---
v2: New patch.

 drivers/usb/host/dwc2.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/host/dwc2.c b/drivers/usb/host/dwc2.c
index 05d21b7948f5..e370d29ffc8e 100644
--- a/drivers/usb/host/dwc2.c
+++ b/drivers/usb/host/dwc2.c
@@ -756,24 +756,18 @@ int chunk_msg(struct usb_device *dev, unsigned long pipe, int *pid, int in,
 	debug("%s: msg: pipe %lx pid %d in %d len %d\n", __func__, pipe, *pid,
 	      in, len);
 
-	if (len > DWC2_DATA_BUF_SIZE) {
-		printf("%s: %d is more then available buffer size (%d)\n",
-		       __func__, len, DWC2_DATA_BUF_SIZE);
-		dev->status = 0;
-		dev->act_len = 0;
-		return -EINVAL;
-	}
-
 	do {
 		/* Initialize channel */
 		dwc_otg_hc_init(regs, DWC2_HC_CHANNEL, devnum, ep, in, eptype,
 				max);
 
 		xfer_len = len - done;
-		/* Make sure that xfer_len is a multiple of max packet size. */
 		if (xfer_len > CONFIG_DWC2_MAX_TRANSFER_SIZE)
 			xfer_len = CONFIG_DWC2_MAX_TRANSFER_SIZE - max + 1;
+		if (xfer_len > DWC2_DATA_BUF_SIZE)
+			xfer_len = DWC2_DATA_BUF_SIZE - max + 1;
 
+		/* Make sure that xfer_len is a multiple of max packet size. */
 		if (xfer_len > 0) {
 			num_packets = (xfer_len + max - 1) / max;
 			if (num_packets > CONFIG_DWC2_MAX_PACKET_COUNT) {
-- 
1.9.1

[U-Boot] [PATCH V2 1/2] usb: dwc2: fix aligned buffer usage

[Marek Vasut]

On Sunday, March 08, 2015 at 06:08:13 PM, Stephen Warren wrote:
> The original aligned_buffer usage:
> a) Uselessly copied data into the aligned buffer even for IN
>    transactions. Fix this my making the copy conditional.
> b) Always programmed the HW to transfer to/from the start of the aligned
>    buffer. This worked fine for OUT transactions since the memcpy copied
>    the OUT data to this location too. However, for large IN transactions,
>    since the copy from the aligned buffer to the "client" buffer was
>    deferred until after all chunks were transferred. it resulted in each
>    chunk's transfer over-writing the data for the first transfer. Fix
>    this by copying IN data as soon as it's received.
> 
> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>

Applied to u-boot-usb/topic/dwc2, thanks. I would like to see more
testing from others if possible, otherwise this will go in after
2015.04 if you're fine with that.

Best regards,
Marek Vasut

[U-Boot] [PATCH V2 1/2] usb: dwc2: fix aligned buffer usage

[Stephen Warren]

On 03/09/2015 06:46 AM, Marek Vasut wrote:
> On Sunday, March 08, 2015 at 06:08:13 PM, Stephen Warren wrote:
>> The original aligned_buffer usage:
>> a) Uselessly copied data into the aligned buffer even for IN
>>     transactions. Fix this my making the copy conditional.
>> b) Always programmed the HW to transfer to/from the start of the aligned
>>     buffer. This worked fine for OUT transactions since the memcpy copied
>>     the OUT data to this location too. However, for large IN transactions,
>>     since the copy from the aligned buffer to the "client" buffer was
>>     deferred until after all chunks were transferred. it resulted in each
>>     chunk's transfer over-writing the data for the first transfer. Fix
>>     this by copying IN data as soon as it's received.
>>
>> Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
>
> Applied to u-boot-usb/topic/dwc2, thanks. I would like to see more
> testing from others if possible, otherwise this will go in after
> 2015.04 if you're fine with that.

Yes, that makes sense at this point in the cycle.

BTW, I should have mentioned the result of these on the RPi, although 
they're much the same as with the earlier patch you posted to support 
 >max_packet_size control transfers:

* I can enumerate a USB keyboard directly attached to the SoC, without 
intervening hub.

* If I enable USB keyboard support in U-Boot, and configure it to poll 
via the control EP or interrupt EP (I implemented the submit_interrupt 
function identically to submit_bulk), it will roughly work, except:

** The system usually hangs up very shortly after detecting the USB 
keyboard. Sometimes it lasts a long time though. This appears to be a 
hard hang; if I force the timer module to generate an IRQ, then 
typically I would see U-Boot spew the PC/SP/... when the IRQ fires. 
However, if the timer IRQ is scheduled to fire after the USB-related 
hang, nothing is printed. I need to try JTAG I guess.

** When polling via the interrupt EP, the character repeat is massively 
too fast; much faster than on e.g. NVIDIA Tegra Seaboard with the same 
keyboard polling option selected. It seems that USB IN transactions 
often repeat without actually writing to the IN data buffer, although I 
can't see any status in the registers indicating that the transaction 
was NAK'd/NYET'd/failed. I wonder if I need to manually delay 
transactions with this controller - do EHCI controllers hold off 
interrupt transactions automatically and only submit them to the bus at 
a low rate?