diff --git a/adb/daemon/usb.cpp b/adb/daemon/usb.cpp index a35c210f9..16f4b6d3f 100644 --- a/adb/daemon/usb.cpp +++ b/adb/daemon/usb.cpp @@ -49,16 +49,23 @@ using namespace std::chrono_literals; #define MAX_PACKET_SIZE_HS 512 #define MAX_PACKET_SIZE_SS 1024 -// Writes larger than 16k fail on some devices (seed with 3.10.49-g209ea2f in particular). -#define USB_FFS_MAX_WRITE 16384 - -// The kernel allocates a contiguous buffer for reads, which can fail for large ones due to -// fragmentation. 16k chosen arbitrarily to match the write limit. -#define USB_FFS_MAX_READ 16384 +// Kernels before 3.3 have a 16KiB transfer limit That limit was replaced +// with a 16MiB global limit in 3.3, but each URB submitted required a +// contiguous kernel allocation, so you would get ENOMEM if you tried to +// send something larger than the biggest available contiguous kernel +// memory region. Large contiguous allocations could be unreliable +// on a device kernel that has been running for a while fragmenting its +// memory so we start with a larger allocation, and shrink the amount if +// necessary. +#define USB_FFS_BULK_SIZE 16384 #define cpu_to_le16(x) htole16(x) #define cpu_to_le32(x) htole32(x) +#define FUNCTIONFS_ENDPOINT_ALLOC _IOR('g', 231, __u32) + +static constexpr size_t ENDPOINT_ALLOC_RETRIES = 10; + static int dummy_fd = -1; struct func_desc { @@ -229,6 +236,7 @@ bool init_functionfs(struct usb_handle* h) { ssize_t ret; struct desc_v1 v1_descriptor; struct desc_v2 v2_descriptor; + size_t retries = 0; v2_descriptor.header.magic = cpu_to_le32(FUNCTIONFS_DESCRIPTORS_MAGIC_V2); v2_descriptor.header.length = cpu_to_le32(sizeof(v2_descriptor)); @@ -287,6 +295,29 @@ bool init_functionfs(struct usb_handle* h) { goto err; } + h->max_rw = MAX_PAYLOAD; + while (h->max_rw >= USB_FFS_BULK_SIZE && retries < ENDPOINT_ALLOC_RETRIES) { + int ret_in = ioctl(h->bulk_in, FUNCTIONFS_ENDPOINT_ALLOC, static_cast<__u32>(h->max_rw)); + int errno_in = errno; + int ret_out = ioctl(h->bulk_out, FUNCTIONFS_ENDPOINT_ALLOC, static_cast<__u32>(h->max_rw)); + int errno_out = errno; + + if (ret_in || ret_out) { + if (errno_in == ENODEV || errno_out == ENODEV) { + std::this_thread::sleep_for(100ms); + retries += 1; + continue; + } + h->max_rw /= 2; + } else { + return true; + } + } + + D("[ adb: cannot call endpoint alloc: errno=%d ]", errno); + // Kernel pre-allocation could have failed for recoverable reasons. + // Continue running with a safe max rw size. + h->max_rw *= 2; return true; err: @@ -340,7 +371,7 @@ static int usb_ffs_write(usb_handle* h, const void* data, int len) { const char* buf = static_cast(data); while (len > 0) { - int write_len = std::min(USB_FFS_MAX_WRITE, len); + int write_len = std::min(h->max_rw, len); int n = adb_write(h->bulk_in, buf, write_len); if (n < 0) { D("ERROR: fd = %d, n = %d: %s", h->bulk_in, n, strerror(errno)); @@ -359,7 +390,7 @@ static int usb_ffs_read(usb_handle* h, void* data, int len) { char* buf = static_cast(data); while (len > 0) { - int read_len = std::min(USB_FFS_MAX_READ, len); + int read_len = std::min(h->max_rw, len); int n = adb_read(h->bulk_out, buf, read_len); if (n < 0) { D("ERROR: fd = %d, n = %d: %s", h->bulk_out, n, strerror(errno)); diff --git a/adb/daemon/usb.h b/adb/daemon/usb.h index 1d85405a6..55b59952f 100644 --- a/adb/daemon/usb.h +++ b/adb/daemon/usb.h @@ -20,13 +20,6 @@ #include #include -// Writes larger than 16k fail on some devices (seed with 3.10.49-g209ea2f in particular). -#define USB_FFS_MAX_WRITE 16384 - -// The kernel allocates a contiguous buffer for reads, which can fail for large ones due to -// fragmentation. 16k chosen arbitrarily to match the write limit. -#define USB_FFS_MAX_READ 16384 - struct usb_handle { usb_handle() : kicked(false) { } @@ -45,6 +38,8 @@ struct usb_handle { int control = -1; int bulk_out = -1; /* "out" from the host's perspective => source for adbd */ int bulk_in = -1; /* "in" from the host's perspective => sink for adbd */ + + int max_rw; }; bool init_functionfs(struct usb_handle* h);