openwrt/target/linux/bcm27xx/patches-4.19/950-0667-dwc_otg-use-align_buf-for-small-IN-control-transfers.patch
Adrian Schmutzler 7d7aa2fd92 brcm2708: rename target to bcm27xx
This change makes the names of Broadcom targets consistent by using
the common notation based on SoC/CPU ID (which is used internally
anyway), bcmXXXX instead of brcmXXXX.
This is even used for target TITLE in make menuconfig already,
only the short target name used brcm so far.

Despite, since subtargets range from bcm2708 to bcm2711, it seems
appropriate to use bcm27xx instead of bcm2708 (again, as already done
for BOARDNAME).

This also renames the packages brcm2708-userland and brcm2708-gpu-fw.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>
2020-02-14 14:10:51 +01:00

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Diff

From 0c6190fa3cfeafd773b51b751a473d6775c23309 Mon Sep 17 00:00:00 2001
From: P33M <2474547+P33M@users.noreply.github.com>
Date: Wed, 14 Aug 2019 14:35:50 +0100
Subject: [PATCH] dwc_otg: use align_buf for small IN control transfers
(#3150)
The hardware will do a 4-byte write to memory on any IN packet received
that is between 1 and 3 bytes long. This tramples memory in the uvcvideo
driver, as it uses a sequence of 1- and 2-byte control transfers to
query the min/max/range/step of each individual camera control and
gives us buffers that are offsets into a struct.
Catch small control transfers in the data phase and use the align_buf
to bounce the correct number of bytes into the URB's buffer.
In general, short packets on non-control endpoints should be OK as URBs
should have enough buffer space for a wMaxPacket size transfer.
See: https://github.com/raspberrypi/linux/issues/3148
Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
---
drivers/usb/host/dwc_otg/dwc_otg_hcd.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
--- a/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
+++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd.c
@@ -1182,6 +1182,7 @@ static void assign_and_init_hc(dwc_otg_h
dwc_otg_qtd_t *qtd;
dwc_otg_hcd_urb_t *urb;
void* ptr = NULL;
+ uint16_t wLength;
uint32_t intr_enable;
unsigned long flags;
gintmsk_data_t gintmsk = { .d32 = 0, };
@@ -1293,6 +1294,23 @@ static void assign_and_init_hc(dwc_otg_h
break;
case DWC_OTG_CONTROL_DATA:
DWC_DEBUGPL(DBG_HCDV, " Control data transaction\n");
+ /*
+ * Hardware bug: small IN packets with length < 4
+ * cause a 4-byte write to memory. We can only catch
+ * the case where we know a short packet is going to be
+ * returned in a control transfer, as the length is
+ * specified in the setup packet. This is only an issue
+ * for drivers that insist on packing a device's various
+ * properties into a struct and querying them one at a
+ * time (uvcvideo).
+ * Force the use of align_buf so that the subsequent
+ * memcpy puts the right number of bytes in the URB's
+ * buffer.
+ */
+ wLength = ((uint16_t *)urb->setup_packet)[3];
+ if (hc->ep_is_in && wLength < 4)
+ ptr = hc->xfer_buff;
+
hc->data_pid_start = qtd->data_toggle;
break;
case DWC_OTG_CONTROL_STATUS: