aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm2708/patches-4.19/950-0697-dwc_otg-use-align_buf-for-small-IN-control-transfers.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0697-dwc_otg-use-align_buf-for-small-IN-control-transfers.patch')
-rw-r--r--target/linux/brcm2708/patches-4.19/950-0697-dwc_otg-use-align_buf-for-small-IN-control-transfers.patch59
1 files changed, 59 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0697-dwc_otg-use-align_buf-for-small-IN-control-transfers.patch b/target/linux/brcm2708/patches-4.19/950-0697-dwc_otg-use-align_buf-for-small-IN-control-transfers.patch
new file mode 100644
index 0000000000..fbfef019b0
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.19/950-0697-dwc_otg-use-align_buf-for-small-IN-control-transfers.patch
@@ -0,0 +1,59 @@
+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: