From 2a15e634d80f78cf2d8aa16ecf0f3cf930e277b4 Mon Sep 17 00:00:00 2001 From: Hui Wang Date: Sun, 17 Nov 2019 10:31:46 +0800 Subject: [PATCH] dwc_otg: checking the urb->transfer_buffer too early (#3332) After enable the HIGHMEM and VMSPLIT_3G, the dwc_otg driver doesn't work well on Pi2/3 boards with 1G physical ram. Users experience the failure when copying a file of 600M size to the USB stick. And at the same time, the dmesg shows: usb 1-1.1.2: reset high-speed USB device number 8 using dwc_otg sd 0:0:0:0: [sda] tag#0 FAILED Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK blk_update_request: I/O error, dev sda, sector 3024048 op 0x1:(WRITE) flags 0x4000 phys_seg 15 prio class 0 When this happens, the sg_buf sent to the driver is located in the highmem region, the usb_sg_init() in the core/message.c will leave transfer_buffer to NULL if the sg_buf is in highmem, but in the dwc_otg driver, it returns -EINVAL unconditionally if transfer_buffer is NULL. The driver can handle the situation of buffer to be NULL, if it is in DMA mode, it will convert an address from transfer_dma. But if the conversion fails or it is in the PIO mode, we should check buffer and return -EINVAL if it is NULL. BugLink: https://bugs.launchpad.net/bugs/1852510 Signed-off-by: Hui Wang --- drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- a/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c +++ b/drivers/usb/host/dwc_otg/dwc_otg_hcd_linux.c @@ -821,10 +821,6 @@ static int dwc_otg_urb_enqueue(struct us dump_urb_info(urb, "dwc_otg_urb_enqueue"); } #endif - - if (!urb->transfer_buffer && urb->transfer_buffer_length) - return -EINVAL; - if ((usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) || (usb_pipetype(urb->pipe) == PIPE_INTERRUPT)) { if (!dwc_otg_hcd_is_bandwidth_allocated @@ -881,6 +877,13 @@ static int dwc_otg_urb_enqueue(struct us &urb->transfer_dma, buf); } + if (!buf && urb->transfer_buffer_length) { + DWC_FREE(dwc_otg_urb); + DWC_ERROR("transfer_buffer is NULL in PIO mode or both " + "transfer_buffer and transfer_dma are NULL in DMA mode\n"); + return -EINVAL; + } + if (!(urb->transfer_flags & URB_NO_INTERRUPT)) flags |= URB_GIVEBACK_ASAP; if (urb->transfer_flags & URB_ZERO_PACKET)