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Merge "fastboot: Increase maximum usbfs bulk size for writes to 256KiB" into main

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Treehugger Robot 2024-02-15 03:47:49 +00:00 committed by Gerrit Code Review
commit c0e1b607d3
1 changed files with 37 additions and 19 deletions
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56
fastboot/usb_linux.cpp
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@ -83,7 +83,18 @@ using namespace std::chrono_literals;
// be reliable.
// 256KiB seems to work, but 1MiB bulk transfers lock up my z620 with a 3.13
// kernel.
#define MAX_USBFS_BULK_SIZE (16 * 1024)
// 128KiB was experimentally found to be enough to saturate the bus at
// SuperSpeed+, so we first try double that for writes. If the operation fails
// due to a lack of contiguous regions (or an ancient kernel), try smaller sizes
// until we find one that works (see LinuxUsbTransport::Write). Reads are less
// performance critical so for now just use a known good size.
#define MAX_USBFS_BULK_WRITE_SIZE (256 * 1024)
#define MAX_USBFS_BULK_READ_SIZE (16 * 1024)
// This size should pretty much always work (it's compatible with pre-3.3
// kernels and it's what we used to use historically), so if it doesn't work
// something has gone badly wrong.
#define MIN_USBFS_BULK_WRITE_SIZE (16 * 1024)
struct usb_handle
{
@ -108,6 +119,7 @@ class LinuxUsbTransport : public UsbTransport {
private:
std::unique_ptr<usb_handle> handle_;
const uint32_t ms_timeout_;
size_t max_usbfs_bulk_write_size_ = MAX_USBFS_BULK_WRITE_SIZE;
DISALLOW_COPY_AND_ASSIGN(LinuxUsbTransport);
};
@ -415,26 +427,32 @@ ssize_t LinuxUsbTransport::Write(const void* _data, size_t len)
}
auto submit_urb = [&](size_t i) {
int xfer = (len > MAX_USBFS_BULK_SIZE) ? MAX_USBFS_BULK_SIZE : len;
while (true) {
int xfer = (len > max_usbfs_bulk_write_size_) ? max_usbfs_bulk_write_size_ : len;
urb[i].type = USBDEVFS_URB_TYPE_BULK;
urb[i].endpoint = handle_->ep_out;
urb[i].buffer_length = xfer;
urb[i].buffer = data;
urb[i].usercontext = (void *)i;
urb[i].type = USBDEVFS_URB_TYPE_BULK;
urb[i].endpoint = handle_->ep_out;
urb[i].buffer_length = xfer;
urb[i].buffer = data;
urb[i].usercontext = (void *)i;
int n = ioctl(handle_->desc, USBDEVFS_SUBMITURB, &urb[i]);
if (n != 0) {
DBG("ioctl(USBDEVFS_SUBMITURB) failed\n");
return false;
int n = ioctl(handle_->desc, USBDEVFS_SUBMITURB, &urb[i]);
if (n != 0) {
if (errno == ENOMEM && max_usbfs_bulk_write_size_ > MIN_USBFS_BULK_WRITE_SIZE) {
max_usbfs_bulk_write_size_ /= 2;
continue;
}
DBG("ioctl(USBDEVFS_SUBMITURB) failed\n");
return false;
}
pending[i] = true;
count += xfer;
len -= xfer;
data += xfer;
return true;
}
pending[i] = true;
count += xfer;
len -= xfer;
data += xfer;
return true;
};
auto reap_urb = [&](size_t i) {
@ -500,7 +518,7 @@ ssize_t LinuxUsbTransport::Read(void* _data, size_t len)
}
while (len > 0) {
int xfer = (len > MAX_USBFS_BULK_SIZE) ? MAX_USBFS_BULK_SIZE : len;
int xfer = (len > MAX_USBFS_BULK_READ_SIZE) ? MAX_USBFS_BULK_READ_SIZE : len;
bulk.ep = handle_->ep_in;
bulk.len = xfer;