lkml.org 
[lkml]   [2005]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [ patch 1/7] drivers/serial/jsm: new serial device driver
Wen Xiong wrote:


General comment: This driver has -way- too many global variables.

Normal drivers should associate state information with each instance of
a device (e.g. each struct pci_dev), not globally.


> +/*
> + * Globals
> + */
> +uint jsm_NumBoards,current_NumBoards;
> +struct board_t *jsm_Board[MAXBOARDS];
> +char *jsm_board_slot[MAXBOARDS];
> +spinlock_t jsm_global_lock = SPIN_LOCK_UNLOCKED;
> +int jsm_driver_state = DRIVER_INITIALIZED;
> +ulong jsm_poll_counter;
> +uint jsm_Major;
> +int jsm_debug;
> +int jsm_rawreadok;
> +int jsm_trcbuf_size;

Eliminate MAXBOARDS. Such static limits are completely unnecessary.


> +/*
> + * Static vars.
> + */
> +static uint jsm_major_control_registered = FALSE;
> +static uint jsm_driver_start = FALSE;

Eliminate jsm_driver_start. This is unnecessary also.



> +/*
> + * Poller stuff
> + */
> +static spinlock_t jsm_poll_lock = SPIN_LOCK_UNLOCKED;
> +static ulong jsm_poll_time; /* Time of next poll */
> +static ulong jsm_poll_tick = 50; /* Poll interval - 20 ms */
> +
> +static struct timer_list jsm_poll_timer = {
> + .function = jsm_poll_handler
> +};
> +
> +static struct pci_device_id jsm_pci_tbl[] = {
> + { DIGI_VID, PCI_DEVICE_NEO_4_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
> + { DIGI_VID, PCI_DEVICE_NEO_8_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 1 },
> + { DIGI_VID, PCI_DEVICE_NEO_2DB9_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 2 },
> + { DIGI_VID, PCI_DEVICE_NEO_2DB9PRI_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 3 },
> + { DIGI_VID, PCI_DEVICE_NEO_2RJ45_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 4 },
> + { DIGI_VID, PCI_DEVICE_NEO_2RJ45PRI_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 5 },
> + { DIGI_VID, PCI_DEVICE_NEO_1_422_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 6 },
> + { DIGI_VID, PCI_DEVICE_NEO_1_422_485_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 7 },
> + { DIGI_VID, PCI_DEVICE_NEO_2_422_485_DID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 8 },
> + {0,} /* 0 terminated list. */

Don't create your own constants, use standard linux/pci_ids.h ones.


> +MODULE_DEVICE_TABLE(pci, jsm_pci_tbl);
> +
> +struct board_id {
> + uchar *name;
> + uint maxports;
> +};
> +
> +static struct board_id jsm_Ids[] = {
> + { PCI_DEVICE_NEO_4_PCI_NAME, 4 },
> + { PCI_DEVICE_NEO_8_PCI_NAME, 8 },
> + { PCI_DEVICE_NEO_2DB9_PCI_NAME, 2 },
> + { PCI_DEVICE_NEO_2DB9PRI_PCI_NAME, 2 },
> + { PCI_DEVICE_NEO_2RJ45_PCI_NAME, 2 },
> + { PCI_DEVICE_NEO_2RJ45PRI_PCI_NAME, 2 },
> + { PCI_DEVICE_NEO_1_422_PCI_NAME, 1 },
> + { PCI_DEVICE_NEO_1_422_485_PCI_NAME, 1 },
> + { PCI_DEVICE_NEO_2_422_485_PCI_NAME, 2 },
> + { NULL, 0 }
> +};
> +
> +struct pci_driver jsm_driver = {
> + .name = "jsm",
> + .probe = jsm_init_one,
> + .id_table = jsm_pci_tbl,
> + .remove = __devexit_p(jsm_remove_one),
> +};
> +
> +char *jsm_state_text[] = {
> + "Board Failed",
> + "Board Found",
> + "Board READY",
> +};
> +
> +char *jsm_driver_state_text[] = {
> + "Driver Initialized",
> + "Driver Ready."
> +};
> +
> +/*
> + * jsm_init_globals()
> + *
> + * This is where we initialize the globals from the static insmod
> + * configuration variables. These are declared near the head of
> + * this file.
> + */
> +static void jsm_init_globals(void)
> +{
> + int i = 0;
> +
> + jsm_rawreadok = rawreadok;
> + jsm_trcbuf_size = trcbuf_size;
> + jsm_debug = debug;
> +
> + for (i = 0; i < MAXBOARDS; i++) {
> + jsm_Board[i] = NULL;
> + jsm_board_slot[i] = (char *)kmalloc(20, GFP_KERNEL);
> + memset(jsm_board_slot[i], 0, 20);
> + }
> +
> + init_timer(&jsm_poll_timer);
> +}

When MAXBOARDS is eliminated, and the poll timer is made per-device,
this code will go away.


> +/*
> + * jsm_poll_handler
> + *
> + * As each timer expires, it determines (a) whether the "transmit"
> + * waiter needs to be woken up, and (b) whether the poller needs to
> + * be rescheduled.
> + */
> +static void jsm_poll_handler(ulong dummy)
> +{
> + struct board_t *brd;
> + unsigned long lock_flags;
> + int i;
> +
> + jsm_poll_counter++;
> +
> + /*
> + * Do not start the board state machine until
> + * driver tells us its up and running, and has
> + * everything it needs.
> + */
> + if (jsm_driver_state != DRIVER_READY)
> + goto schedule_poller;
> +
> + /* Go thru each board, kicking off a tasklet for each if needed */
> + for (i = 0; i < jsm_NumBoards; i++) {
> + if (jsm_Board[i] == NULL) continue;
> + brd = jsm_Board[i];
> +
> + spin_lock_irqsave(&brd->bd_lock, lock_flags);
> +
> + /* If board is in a failed state, don't bother scheduling a tasklet */
> + if (brd->state == BOARD_FAILED) {
> + spin_lock_irqsave(&brd->bd_lock, lock_flags);
> + continue;
> + }
> +
> + spin_unlock_irqrestore(&brd->bd_lock, lock_flags);
> + }
> +
> +schedule_poller:
> +
> + /*
> + * Schedule ourself back at the nominal wakeup interval.
> + */
> + if (current_NumBoards >= 0) {
> + ulong time;
> +
> + spin_lock_irqsave(&jsm_poll_lock, lock_flags);
> + jsm_poll_time += jsm_jiffies_from_ms(jsm_poll_tick);
> +
> + time = jsm_poll_time - jiffies;
> +
> + if ((ulong) time >= 2 * jsm_poll_tick)
> + jsm_poll_time = jiffies + jsm_jiffies_from_ms(jsm_poll_tick);
> +
> + jsm_poll_timer.expires = jsm_poll_time;
> + spin_unlock_irqrestore(&jsm_poll_lock, lock_flags);
> +
> + add_timer(&jsm_poll_timer);
> + }
> +}

Don't use a single timer for all boards. This makes information
needlessly global.


> +/*
> + * Start of driver.
> + */
> +static int jsm_start(void)
> +{
> + int rc = 0;
> + unsigned long lock_flags;
> +
> + if (!jsm_driver_start) {
> + jsm_driver_start = TRUE;

As noted earlier, jsm_driver_start is completely pointless.

jsm_start() is the first function called in module_init(), and is never
called from anywhere else.


> + /* make sure that the globals are init'd before we do anything else */
> + jsm_init_globals();
> + jsm_NumBoards = 0;
> + current_NumBoards = -1;
> +
> + APR(("For the tools package or updated drivers please visit http://www.digi.com\n"));
> +
> + /*
> + * Register our base character device into the kernel.
> + * This allows the download daemon to connect to the downld device
> + * before any of the boards are init'ed.
> + */
> + if (!jsm_major_control_registered) {
> + /*
> + * Register management/dpa devices
> + */
> + rc = register_chrdev(0, "jsm", &jsm_BoardFops);
> + if (rc <= 0) {
> + APR(("Can't register jsm driver device (%d)\n", rc));
> + return -ENXIO;
> + }
> + jsm_Major = rc;
> + jsm_major_control_registered = TRUE;
> + }
> +
> + /*
> + * Register our basic stuff in /proc/jsm
> + */
> + jsm_proc_register_basic_prescan();
> +
> + if (rc < 0) {
> + APR(("tty preinit - not enough memory (%d)\n", rc));
> + return rc;
> + }

Why is this not in sysfs?


> + /* Start the poller */
> + spin_lock_irqsave(&jsm_poll_lock, lock_flags);
> + jsm_poll_time = jiffies + jsm_jiffies_from_ms(jsm_poll_tick);
> + jsm_poll_timer.expires = jsm_poll_time;
> + spin_unlock_irqrestore(&jsm_poll_lock, lock_flags);
> +
> + add_timer(&jsm_poll_timer);

It's silly to add a timer and start polling, when you have nothing to poll.

But that's ok... this code will go away when the poll timer is made
per-device.


> + jsm_driver_state = DRIVER_READY;
> + }
> + return rc;
> +}
> +
> +static int jsm_finalize_board_init(struct board_t *brd)
> +{
> + int rc = 0;
> +
> + DPR_INIT(("jsm_finalize_board_init() - start\n"));
> +
> + if (!brd || brd->magic != JSM_BOARD_MAGIC)
> + return -ENODEV;
> +
> + DPR_INIT(("jsm_finalize_board_init() - start #2\n"));
> +
> + if (brd->irq) {
> + rc = request_irq(brd->irq, brd->bd_ops->intr, SA_INTERRUPT|SA_SHIRQ, "JSM", brd);
> +
> + if (rc) {
> + printk(KERN_WARNING "Failed to hook IRQ %d\n",brd->irq);
> + brd->state = BOARD_FAILED;
> + brd->dpastatus = BD_NOFEP;
> + rc = -ENODEV;
> + } else {
> + DPR_INIT(("Requested and received usage of IRQ %d\n", brd->irq));
> + }
> + }
> + return rc;
> +}
> +
> +/*
> + * jsm_found_board()
> + *
> + * A board has been found, init it.
> + */
> +static int jsm_found_board(struct pci_dev *pdev, int id)
> +{
> + struct board_t *brd;
> + unsigned int pci_irq;
> + int i = 0;
> + int rc = 0;
> + int index;
> + int wen_board;
> + int hotplug = 0;
> +
> + wen_board = jsm_NumBoards;
> + for (index = 0; index < jsm_NumBoards; index++) {
> + if (!strcmp(jsm_board_slot[index], pdev->slot_name)) {
> + wen_board = index;
> + hotplug = 1;
> + break;
> + }
> + }

It is very wrong to store boards based on pdev->slot_name.

However, this goes away when more state is made per-device.



> + brd = jsm_Board[wen_board] =
> + (struct board_t *)kmalloc(sizeof(struct board_t), GFP_KERNEL);
> + if (!brd) {
> + APR(("memory allocation for board structure failed\n"));
> + return -ENOMEM;
> + }
> + memset(brd, 0, sizeof(struct board_t));
> +
> + /* store the info for the board we've found */
> + brd->magic = JSM_BOARD_MAGIC;
> + brd->boardnum = wen_board;
> + brd->vendor = jsm_pci_tbl[id].vendor;
> + brd->device = jsm_pci_tbl[id].device;
> + brd->pci_bus = pdev->bus->number;
> + brd->pci_slot = PCI_SLOT(pdev->devfn);

You should not need this information.


> + brd->pci_dev = pdev;
> + brd->name = jsm_Ids[id].name;
> + brd->maxports = jsm_Ids[id].maxports;
> + brd->dpastatus = BD_NOFEP;
> + strcpy(jsm_board_slot[wen_board],pdev->slot_name);
> + init_waitqueue_head(&brd->state_wait);
> +
> + spin_lock_init(&brd->bd_lock);
> + spin_lock_init(&brd->bd_intr_lock);
> +
> + brd->state = BOARD_FOUND;
> +
> + for (i = 0; i < MAXPORTS; i++)
> + brd->channels[i] = NULL;
> +
> + /* store which card & revision we have */
> + pci_read_config_word(pdev, PCI_SUBSYSTEM_VENDOR_ID, &brd->subvendor);
> + pci_read_config_word(pdev, PCI_SUBSYSTEM_ID, &brd->subdevice);

Obtain this information from struct pci_dev. Do not read it manually.


> + pci_irq = pdev->irq;
> + brd->irq = pci_irq;
> +
> + switch(brd->device) {
> +
> + case PCI_DEVICE_NEO_4_DID:
> + case PCI_DEVICE_NEO_8_DID:
> + case PCI_DEVICE_NEO_2DB9_DID:
> + case PCI_DEVICE_NEO_2DB9PRI_DID:
> + case PCI_DEVICE_NEO_2RJ45_DID:
> + case PCI_DEVICE_NEO_2RJ45PRI_DID:
> + case PCI_DEVICE_NEO_1_422_DID:
> + case PCI_DEVICE_NEO_1_422_485_DID:
> + case PCI_DEVICE_NEO_2_422_485_DID:

use standard pci_ids.h constants.


> + /*
> + * This chip is set up 100% when we get to it.
> + * No need to enable global interrupts or anything.
> + */
> + brd->dpatype = T_NEO | T_PCIBUS;
> +
> + DPR_INIT(("jsm_found_board - NEO.\n"));
> +
> + /* get the PCI Base Address Registers */
> + brd->membase = pci_resource_start(pdev, 0);
> + brd->membase_end = pci_resource_end(pdev, 0);
> +
> + if (brd->membase & 1)
> + brd->membase &= ~3;
> + else
> + brd->membase &= ~15;
> +
> + /* Assign the board_ops struct */
> + brd->bd_ops = &jsm_neo_ops;
> +
> + brd->bd_uart_offset = 0x200;
> + brd->bd_dividend = 921600;
> +
> + brd->re_map_membase = ioremap(brd->membase, 0x1000);
> + DPR_INIT(("remapped mem: 0x%p\n", brd->re_map_membase));
> + if (!brd->re_map_membase) {
> + kfree(brd);
> + APR(("card has no PCI Memory resources, failing board.\n"));
> + return -ENOMEM;
> + }
> + break;
> +
> + default:
> + APR(("Did not find any compatible Neo or Classic PCI boards in system.\n"));
> + kfree(brd);
> + return -ENXIO;
> + }
> +
> + /*
> + * Do tty device initialization.
> + */
> + rc = jsm_finalize_board_init(brd);
> + if (rc < 0) {
> + APR(("Can't finalize board init (%d)\n", rc));
> + brd->state = BOARD_FAILED;
> + brd->dpastatus = BD_NOFEP;
> + goto failed;
> + }
> +
> + rc = jsm_tty_register(brd);
> + if (rc < 0) {
> + jsm_tty_uninit(brd);
> + APR(("Can't register tty devices (%d)\n", rc));
> + brd->state = BOARD_FAILED;
> + brd->dpastatus = BD_NOFEP;
> + goto failed;
> + }
> +
> + rc = jsm_tty_init(brd);
> + if (rc < 0) {
> + jsm_tty_uninit(brd);
> + APR(("Can't init tty devices (%d)\n", rc));
> + brd->state = BOARD_FAILED;
> + brd->dpastatus = BD_NOFEP;
> + goto failed;
> + }
> +
> + rc = jsm_uart_port_init(brd);
> + if (rc < 0)
> + goto failed;
> +
> + brd->state = BOARD_READY;
> + brd->dpastatus = BD_RUNNING;
> +
> + /* init our poll helper tasklet */
> + tasklet_init(&brd->helper_tasklet, brd->bd_ops->tasklet, (unsigned long) brd);
> +
> + /* Log the information about the board */
> + APR(("board %d: %s (rev %d), irq %d\n",wen_board, brd->name, brd->rev, brd->irq));
> +
> + /*
> + * allocate flip buffer for board.
> + *
> + * Okay to malloc with GFP_KERNEL, we are not at interrupt
> + * context, and there are no locks held.
> + */
> + brd->flipbuf = kmalloc(MYFLIPLEN, GFP_KERNEL);
> + if (!brd->flipbuf) {
> + APR(("memory allocation for flipbuf failed\n"));
> + return -ENOMEM;
> + }

leak on error


> + memset(brd->flipbuf, 0, MYFLIPLEN);
> +
> + jsm_proc_register_basic_postscan(wen_board);
> + wake_up_interruptible(&brd->state_wait);
> +
> + if (!hotplug)
> + jsm_NumBoards++;
> +
> + current_NumBoards++;
> +
> + return 0;
> +
> +failed:
> + kfree(brd);
> + iounmap((void *) brd->re_map_membase);
> + return -ENXIO;
> +}
> +
> +
> +static int jsm_probe1(struct pci_dev *pdev, int card_type)
> +{
> + return jsm_found_board(pdev, card_type);
> +}

eliminate this needless function.


> +/* returns count (>= 0), or negative on error */
> +static int jsm_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
> +{
> + int rc;
> +
> + rc = pci_enable_device(pdev);
> + if (rc) {
> + dev_err(&pdev->dev, "Device enable FAILED\n");
> + return rc;
> + }
> +
> + if ((rc = jsm_probe1(pdev, ent->driver_data))) {
> + dev_err(&pdev->dev, "jsm_probe1 FAILED\n");
> + pci_disable_device(pdev);
> + return rc;
> + }
> + return rc;
> +}

Missing pci_request_regions().


> +/*
> + * jsm_cleanup_board()
> + *
> + * Free all the memory associated with a board
> + */
> +static void jsm_cleanup_board(struct board_t *brd)
> +{
> + int i = 0;
> +
> + if (!brd || brd->magic != JSM_BOARD_MAGIC)
> + return ;
> +
> + if (brd->irq)
> + free_irq(brd->irq, brd);
> +
> + tasklet_kill(&brd->helper_tasklet);
> +
> + if (brd->re_map_membase) {
> + iounmap(brd->re_map_membase);
> + brd->re_map_membase = NULL;
> + }

When will this 'if' test ever fail?


> + /* Free all allocated channels structs */
> + for (i = 0; i < MAXPORTS; i++) {
> + if (brd->channels[i]) {
> + if (brd->channels[i]->ch_rqueue)
> + kfree(brd->channels[i]->ch_rqueue);
> + if (brd->channels[i]->ch_equeue)
> + kfree(brd->channels[i]->ch_equeue);
> + if (brd->channels[i]->ch_wqueue)
> + kfree(brd->channels[i]->ch_wqueue);
> +
> + kfree(brd->channels[i]);
> + brd->channels[i] = NULL;
> + }
> + }
> +
> + if (brd->flipbuf)
> + kfree(brd->flipbuf);
> +
> + jsm_Board[brd->boardnum] = NULL;
> +
> + kfree(brd);
> + current_NumBoards--;
> +}
> +
> +static void jsm_remove_one(struct pci_dev *dev)
> +{
> + int i;
> +
> + for (i = 0; i < jsm_NumBoards; i++) {
> + if ((jsm_Board[i] != NULL) && (jsm_Board[i]->pci_dev == dev)) {
> + jsm_proc_unregister_brd(i);
> + jsm_remove_uart_port(jsm_Board[i]);
> + jsm_tty_uninit(jsm_Board[i]);
> + jsm_cleanup_board(jsm_Board[i]);
> + }
> + }
> +}

pci_disable_device(), pci_release_regions()


> +/*
> + * jsm_init_module()
> + *
> + * Module load. This is where it all starts.
> + */
> +static int __init
> +jsm_init_module(void)
> +{
> + int rc = 0;
> +
> + APR(("%s, Digi International Part Number %s\n", "jsm: 1.1-1-INKERNEL", "40002438_A-INKERNEL"));
> +
> + /*
> + * Initialize global stuff
> + */
> + rc = jsm_start();
> + if (rc < 0)
> + return rc;
> +
> + rc = uart_register_driver(&jsm_uart_driver);
> + if (rc)
> + return rc;

leak on error


> + rc = pci_register_driver(&jsm_driver);
> + if (rc < 0)
> + uart_unregister_driver(&jsm_uart_driver);

leak on error


> + return rc;
> +}
> +
> +module_init(jsm_init_module);
> +
> +/*
> + * jsm_exit_module()
> + *
> + * Module unload. This is where it all ends.
> + */
> +static void __exit
> +jsm_exit_module(void)
> +{
> + int i;
> +
> + del_timer_sync(&jsm_poll_timer);
> +
> + if (jsm_major_control_registered)
> + unregister_chrdev(jsm_Major, "jsm");
> +
> + pci_unregister_driver(&jsm_driver);
> +
> + jsm_proc_unregister_all();
> +
> + for (i = 0; i < MAXBOARDS; i++) {
> + jsm_board_slot[i] = NULL;
> + kfree(jsm_board_slot[i]);
> + }
> + uart_unregister_driver(&jsm_uart_driver);
> +}
> +module_exit(jsm_exit_module);
> +MODULE_LICENSE("GPL");
> +
> +/*
> + * jsm_ioctl_name()
> + *
> + * Returns a text version of each ioctl value.
> + */
> +char *jsm_ioctl_name(int cmd)
> +{
> + switch(cmd) {
> +
> + case TCGETA: return("TCGETA");
> + case TCGETS: return("TCGETS");
> + case TCSETA: return("TCSETA");
> + case TCSETS: return("TCSETS");
> + case TCSETAW: return("TCSETAW");
> + case TCSETSW: return("TCSETSW");
> + case TCSETAF: return("TCSETAF");
> + case TCSETSF: return("TCSETSF");
> + case TCSBRK: return("TCSBRK");
> + case TCXONC: return("TCXONC");
> + case TCFLSH: return("TCFLSH");
> + case TIOCGSID: return("TIOCGSID");
> +
> + case TIOCGETD: return("TIOCGETD");
> + case TIOCSETD: return("TIOCSETD");
> + case TIOCGWINSZ: return("TIOCGWINSZ");
> + case TIOCSWINSZ: return("TIOCSWINSZ");
> +
> + case TIOCMGET: return("TIOCMGET");
> + case TIOCMSET: return("TIOCMSET");
> + case TIOCMBIS: return("TIOCMBIS");
> + case TIOCMBIC: return("TIOCMBIC");
> +
> + /* from digi.h */
> + case DIGI_SETA: return("DIGI_SETA");
> + case DIGI_SETAW: return("DIGI_SETAW");
> + case DIGI_SETAF: return("DIGI_SETAF");
> + case DIGI_SETFLOW: return("DIGI_SETFLOW");
> + case DIGI_SETAFLOW: return("DIGI_SETAFLOW");
> + case DIGI_GETFLOW: return("DIGI_GETFLOW");
> + case DIGI_GETAFLOW: return("DIGI_GETAFLOW");
> + case DIGI_GETA: return("DIGI_GETA");
> + case DIGI_GEDELAY: return("DIGI_GEDELAY");
> + case DIGI_SEDELAY: return("DIGI_SEDELAY");
> + case DIGI_GETCUSTOMBAUD: return("DIGI_GETCUSTOMBAUD");
> + case DIGI_SETCUSTOMBAUD: return("DIGI_SETCUSTOMBAUD");
> + case TIOCMODG: return("TIOCMODG");
> + case TIOCMODS: return("TIOCMODS");
> + case TIOCSDTR: return("TIOCSDTR");
> + case TIOCCDTR: return("TIOCCDTR");
> +
> + default: return("unknown");
> + }

Eliminate this, or make it debug-only.

Jeff



-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:10    [W:0.071 / U:0.988 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site