From: Erik Rull <erik.rull@rdsoftware.de>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH] usb-host: rip out legacy procfs support
Date: Mon, 19 Dec 2011 18:33:43 +0100 [thread overview]
Message-ID: <4EEF7577.3060107@rdsoftware.de> (raw)
In-Reply-To: <1324034837-13962-1-git-send-email-kraxel@redhat.com>
Gerd Hoffmann wrote:
> This patch removes support for parsing /proc/bus/usb/devices for device
> discovery. The code lacks a few features compared to the sysfs code and
> is also bitrotting as everybody has sysfs these days.
>
> This implies having sysfs mounted is mandatory now to use the usb-host
> driver. udev isn't required though. qemu will prefer the udev-managed
> device nodes below /dev/bus/usb, but in case this directory isn't preset
> qemu will use the device nodes below /proc/bus/usb (default usbfs mount
> point).
>
> Bottom line: make sure you have both sysfs and usbfs mounted properly,
> and everything should continue to work as it did before.
>
> Signed-off-by: Gerd Hoffmann<kraxel@redhat.com>
> ---
> usb-linux.c | 327 ++++++++---------------------------------------------------
> 1 files changed, 42 insertions(+), 285 deletions(-)
>
> diff --git a/usb-linux.c b/usb-linux.c
> index ed14bb1..db41104 100644
> --- a/usb-linux.c
> +++ b/usb-linux.c
> @@ -66,23 +66,9 @@ typedef int USBScanFunc(void *opaque, int bus_num, int addr, const char *port,
> #define DPRINTF(...)
> #endif
>
> -#define USBDBG_DEVOPENED "husb: opened %s/devices\n"
> -
> -#define USBPROCBUS_PATH "/proc/bus/usb"
> #define PRODUCT_NAME_SZ 32
> #define MAX_ENDPOINTS 15
> #define MAX_PORTLEN 16
> -#define USBDEVBUS_PATH "/dev/bus/usb"
> -#define USBSYSBUS_PATH "/sys/bus/usb"
> -
> -static char *usb_host_device_path;
> -
> -#define USB_FS_NONE 0
> -#define USB_FS_PROC 1
> -#define USB_FS_DEV 2
> -#define USB_FS_SYS 3
> -
> -static int usb_fs_type;
>
> /* endpoint association data */
> #define ISO_FRAME_DESC_PER_URB 32
> @@ -430,6 +416,31 @@ static void usb_host_async_cancel(USBDevice *dev, USBPacket *p)
> }
> }
>
> +static int usb_host_open_device(int bus, int addr)
> +{
> + const char *usbfs = NULL;
> + char filename[32];
> + struct stat st;
> + int fd, rc;
> +
> + rc = stat("/dev/bus/usb",&st);
> + if (rc == 0&& S_ISDIR(st.st_mode)) {
> + /* udev-created device nodes available */
> + usbfs = "/dev/bus/usb";
> + } else {
> + /* fallback: usbfs mounted below /proc */
> + usbfs = "/proc/bus/usb";
> + }
> +
> + snprintf(filename, sizeof(filename), "%s/%03d/%03d",
> + usbfs, bus, addr);
> + fd = open(filename, O_RDWR | O_NONBLOCK);
> + if (fd< 0) {
> + fprintf(stderr, "husb: open %s: %s\n", filename, strerror(errno));
> + }
> + return fd;
> +}
> +
> static int usb_host_claim_port(USBHostDevice *s)
> {
> #ifdef USBDEVFS_CLAIM_PORT
> @@ -459,12 +470,7 @@ static int usb_host_claim_port(USBHostDevice *s)
> return -1;
> }
>
> - if (!usb_host_device_path) {
> - return -1;
> - }
> - snprintf(line, sizeof(line), "%s/%03d/%03d",
> - usb_host_device_path, s->match.bus_num, hub_addr);
> - s->hub_fd = open(line, O_RDWR | O_NONBLOCK);
> + s->hub_fd = usb_host_open_device(s->match.bus_num, hub_addr);
> if (s->hub_fd< 0) {
> return -1;
> }
> @@ -509,10 +515,6 @@ static int usb_linux_get_num_interfaces(USBHostDevice *s)
> char device_name[64], line[1024];
> int num_interfaces = 0;
>
> - if (usb_fs_type != USB_FS_SYS) {
> - return -1;
> - }
> -
> sprintf(device_name, "%d-%s", s->bus_num, s->port);
> if (!usb_host_read_file(line, sizeof(line), "bNumInterfaces",
> device_name)) {
> @@ -1079,41 +1081,21 @@ static int usb_host_handle_control(USBDevice *dev, USBPacket *p,
> static uint8_t usb_linux_get_alt_setting(USBHostDevice *s,
> uint8_t configuration, uint8_t interface)
> {
> - uint8_t alt_setting;
> - struct usb_ctrltransfer ct;
> - int ret;
> -
> - if (usb_fs_type == USB_FS_SYS) {
> - char device_name[64], line[1024];
> - int alt_setting;
> + char device_name[64], line[1024];
> + int alt_setting;
>
> - sprintf(device_name, "%d-%s:%d.%d", s->bus_num, s->port,
> - (int)configuration, (int)interface);
> + sprintf(device_name, "%d-%s:%d.%d", s->bus_num, s->port,
> + (int)configuration, (int)interface);
>
> - if (!usb_host_read_file(line, sizeof(line), "bAlternateSetting",
> - device_name)) {
> - goto usbdevfs;
> - }
> - if (sscanf(line, "%d",&alt_setting) != 1) {
> - goto usbdevfs;
> - }
> - return alt_setting;
> - }
> -
> -usbdevfs:
> - ct.bRequestType = USB_DIR_IN | USB_RECIP_INTERFACE;
> - ct.bRequest = USB_REQ_GET_INTERFACE;
> - ct.wValue = 0;
> - ct.wIndex = interface;
> - ct.wLength = 1;
> - ct.data =&alt_setting;
> - ct.timeout = 50;
> - ret = ioctl(s->fd, USBDEVFS_CONTROL,&ct);
> - if (ret< 0) {
> + if (!usb_host_read_file(line, sizeof(line), "bAlternateSetting",
> + device_name)) {
> + /* Assume alt 0 on error */
> + return 0;
> + }
> + if (sscanf(line, "%d",&alt_setting) != 1) {
> /* Assume alt 0 on error */
> return 0;
> }
> -
> return alt_setting;
> }
>
> @@ -1262,7 +1244,6 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
> const char *prod_name, int speed)
> {
> int fd = -1, ret;
> - char buf[1024];
>
> trace_usb_host_open_started(bus_num, addr);
>
> @@ -1270,15 +1251,8 @@ static int usb_host_open(USBHostDevice *dev, int bus_num,
> goto fail;
> }
>
> - if (!usb_host_device_path) {
> - perror("husb: USB Host Device Path not set");
> - goto fail;
> - }
> - snprintf(buf, sizeof(buf), "%s/%03d/%03d", usb_host_device_path,
> - bus_num, addr);
> - fd = open(buf, O_RDWR | O_NONBLOCK);
> + fd = usb_host_open_device(bus_num, addr);
> if (fd< 0) {
> - perror(buf);
> goto fail;
> }
> DPRINTF("husb: opened %s\n", buf);
> @@ -1526,149 +1500,6 @@ int usb_host_device_close(const char *devname)
> return -1;
> }
>
> -static int get_tag_value(char *buf, int buf_size,
> - const char *str, const char *tag,
> - const char *stopchars)
> -{
> - const char *p;
> - char *q;
> - p = strstr(str, tag);
> - if (!p) {
> - return -1;
> - }
> - p += strlen(tag);
> - while (qemu_isspace(*p)) {
> - p++;
> - }
> - q = buf;
> - while (*p != '\0'&& !strchr(stopchars, *p)) {
> - if ((q - buf)< (buf_size - 1)) {
> - *q++ = *p;
> - }
> - p++;
> - }
> - *q = '\0';
> - return q - buf;
> -}
> -
> -/*
> - * Use /proc/bus/usb/devices or /dev/bus/usb/devices file to determine
> - * host's USB devices. This is legacy support since many distributions
> - * are moving to /sys/bus/usb
> - */
> -static int usb_host_scan_dev(void *opaque, USBScanFunc *func)
> -{
> - FILE *f = NULL;
> - char line[1024];
> - char buf[1024];
> - int bus_num, addr, speed, device_count;
> - int class_id, product_id, vendor_id, port;
> - char product_name[512];
> - int ret = 0;
> -
> - if (!usb_host_device_path) {
> - perror("husb: USB Host Device Path not set");
> - goto the_end;
> - }
> - snprintf(line, sizeof(line), "%s/devices", usb_host_device_path);
> - f = fopen(line, "r");
> - if (!f) {
> - perror("husb: cannot open devices file");
> - goto the_end;
> - }
> -
> - device_count = 0;
> - bus_num = addr = class_id = product_id = vendor_id = port = 0;
> - speed = -1; /* Can't get the speed from /[proc|dev]/bus/usb/devices */
> - for(;;) {
> - if (fgets(line, sizeof(line), f) == NULL) {
> - break;
> - }
> - if (strlen(line)> 0) {
> - line[strlen(line) - 1] = '\0';
> - }
> - if (line[0] == 'T'&& line[1] == ':') {
> - if (device_count&& (vendor_id || product_id)) {
> - /* New device. Add the previously discovered device. */
> - if (port> 0) {
> - snprintf(buf, sizeof(buf), "%d", port);
> - } else {
> - snprintf(buf, sizeof(buf), "?");
> - }
> - ret = func(opaque, bus_num, addr, buf, class_id, vendor_id,
> - product_id, product_name, speed);
> - if (ret) {
> - goto the_end;
> - }
> - }
> - if (get_tag_value(buf, sizeof(buf), line, "Bus=", " ")< 0) {
> - goto fail;
> - }
> - bus_num = atoi(buf);
> - if (get_tag_value(buf, sizeof(buf), line, "Port=", " ")< 0) {
> - goto fail;
> - }
> - port = atoi(buf);
> - if (get_tag_value(buf, sizeof(buf), line, "Dev#=", " ")< 0) {
> - goto fail;
> - }
> - addr = atoi(buf);
> - if (get_tag_value(buf, sizeof(buf), line, "Spd=", " ")< 0) {
> - goto fail;
> - }
> - if (!strcmp(buf, "5000")) {
> - speed = USB_SPEED_SUPER;
> - } else if (!strcmp(buf, "480")) {
> - speed = USB_SPEED_HIGH;
> - } else if (!strcmp(buf, "1.5")) {
> - speed = USB_SPEED_LOW;
> - } else {
> - speed = USB_SPEED_FULL;
> - }
> - product_name[0] = '\0';
> - class_id = 0xff;
> - device_count++;
> - product_id = 0;
> - vendor_id = 0;
> - } else if (line[0] == 'P'&& line[1] == ':') {
> - if (get_tag_value(buf, sizeof(buf), line, "Vendor=", " ")< 0) {
> - goto fail;
> - }
> - vendor_id = strtoul(buf, NULL, 16);
> - if (get_tag_value(buf, sizeof(buf), line, "ProdID=", " ")< 0) {
> - goto fail;
> - }
> - product_id = strtoul(buf, NULL, 16);
> - } else if (line[0] == 'S'&& line[1] == ':') {
> - if (get_tag_value(buf, sizeof(buf), line, "Product=", "")< 0) {
> - goto fail;
> - }
> - pstrcpy(product_name, sizeof(product_name), buf);
> - } else if (line[0] == 'D'&& line[1] == ':') {
> - if (get_tag_value(buf, sizeof(buf), line, "Cls=", " (")< 0) {
> - goto fail;
> - }
> - class_id = strtoul(buf, NULL, 16);
> - }
> - fail: ;
> - }
> - if (device_count&& (vendor_id || product_id)) {
> - /* Add the last device. */
> - if (port> 0) {
> - snprintf(buf, sizeof(buf), "%d", port);
> - } else {
> - snprintf(buf, sizeof(buf), "?");
> - }
> - ret = func(opaque, bus_num, addr, buf, class_id, vendor_id,
> - product_id, product_name, speed);
> - }
> - the_end:
> - if (f) {
> - fclose(f);
> - }
> - return ret;
> -}
> -
> /*
> * Read sys file-system device file
> *
> @@ -1686,7 +1517,7 @@ static int usb_host_read_file(char *line, size_t line_size,
> int ret = 0;
> char filename[PATH_MAX];
>
> - snprintf(filename, PATH_MAX, USBSYSBUS_PATH "/devices/%s/%s", device_name,
> + snprintf(filename, PATH_MAX, "/sys/bus/usb/devices/%s/%s", device_name,
> device_file);
> f = fopen(filename, "r");
> if (f) {
> @@ -1704,7 +1535,7 @@ static int usb_host_read_file(char *line, size_t line_size,
> * This code is based on Robert Schiele's original patches posted to
> * the Novell bug-tracker https://bugzilla.novell.com/show_bug.cgi?id=241950
> */
> -static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
> +static int usb_host_scan(void *opaque, USBScanFunc *func)
> {
> DIR *dir = NULL;
> char line[1024];
> @@ -1714,9 +1545,10 @@ static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
> char product_name[512];
> struct dirent *de;
>
> - dir = opendir(USBSYSBUS_PATH "/devices");
> + dir = opendir("/sys/bus/usb/devices");
> if (!dir) {
> - perror("husb: cannot open devices directory");
> + perror("husb: opendir /sys/bus/usb/devices");
> + fprintf(stderr, "husb: please make sure sysfs is mounted at /sys\n");
> goto the_end;
> }
>
> @@ -1791,81 +1623,6 @@ static int usb_host_scan_sys(void *opaque, USBScanFunc *func)
> return ret;
> }
>
> -/*
> - * Determine how to access the host's USB devices and call the
> - * specific support function.
> - */
> -static int usb_host_scan(void *opaque, USBScanFunc *func)
> -{
> - Monitor *mon = cur_mon;
> - FILE *f = NULL;
> - DIR *dir = NULL;
> - int ret = 0;
> - const char *fs_type[] = {"unknown", "proc", "dev", "sys"};
> - char devpath[PATH_MAX];
> -
> - /* only check the host once */
> - if (!usb_fs_type) {
> - dir = opendir(USBSYSBUS_PATH "/devices");
> - if (dir) {
> - /* devices found in /dev/bus/usb/ (yes - not a mistake!) */
> - strcpy(devpath, USBDEVBUS_PATH);
> - usb_fs_type = USB_FS_SYS;
> - closedir(dir);
> - DPRINTF(USBDBG_DEVOPENED, USBSYSBUS_PATH);
> - goto found_devices;
> - }
> - f = fopen(USBPROCBUS_PATH "/devices", "r");
> - if (f) {
> - /* devices found in /proc/bus/usb/ */
> - strcpy(devpath, USBPROCBUS_PATH);
> - usb_fs_type = USB_FS_PROC;
> - fclose(f);
> - DPRINTF(USBDBG_DEVOPENED, USBPROCBUS_PATH);
> - goto found_devices;
> - }
> - /* try additional methods if an access method hasn't been found yet */
> - f = fopen(USBDEVBUS_PATH "/devices", "r");
> - if (f) {
> - /* devices found in /dev/bus/usb/ */
> - strcpy(devpath, USBDEVBUS_PATH);
> - usb_fs_type = USB_FS_DEV;
> - fclose(f);
> - DPRINTF(USBDBG_DEVOPENED, USBDEVBUS_PATH);
> - goto found_devices;
> - }
> - found_devices:
> - if (!usb_fs_type) {
> - if (mon) {
> - monitor_printf(mon, "husb: unable to access USB devices\n");
> - }
> - return -ENOENT;
> - }
> -
> - /* the module setting (used later for opening devices) */
> - usb_host_device_path = g_malloc0(strlen(devpath)+1);
> - strcpy(usb_host_device_path, devpath);
> - if (mon) {
> - monitor_printf(mon, "husb: using %s file-system with %s\n",
> - fs_type[usb_fs_type], usb_host_device_path);
> - }
> - }
> -
> - switch (usb_fs_type) {
> - case USB_FS_PROC:
> - case USB_FS_DEV:
> - ret = usb_host_scan_dev(opaque, func);
> - break;
> - case USB_FS_SYS:
> - ret = usb_host_scan_sys(opaque, func);
> - break;
> - default:
> - ret = -EINVAL;
> - break;
> - }
> - return ret;
> -}
> -
> static QEMUTimer *usb_auto_timer;
>
> static int usb_host_auto_scan(void *opaque, int bus_num,
Works fine from my side!
Best regards,
Erik
prev parent reply other threads:[~2011-12-19 17:33 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-16 11:27 [Qemu-devel] [PATCH] usb-host: rip out legacy procfs support Gerd Hoffmann
2011-12-19 17:33 ` Erik Rull [this message]
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