diff options
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.patch | 59 |
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: |