16 files changed, 180 insertions, 54 deletions

diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index c8dfd18bea44..b391776e5bf3 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -130,6 +130,7 @@ config ROCKETPORT
 config CYCLADES
         tristate "Cyclades async mux support"
         depends on SERIAL_NONSTANDARD && (PCI || ISA)
+        select FW_LOADER
         ---help---
           This driver supports Cyclades Z and Y multiserial boards.
           You would need something like this to connect more than two modems to
@@ -726,7 +727,7 @@ config NVRAM
 
 config RTC
         tristate "Enhanced Real Time Clock Support"
-        depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC64 && (!SPARC32 || PCI) && !FRV && !ARM && !SUPERH && !S390
+        depends on !PPC && !PARISC && !IA64 && !M68K && !SPARC && !FRV && !ARM && !SUPERH && !S390
         ---help---
           If you say Y here and create a character special file /dev/rtc with
           major number 10 and minor number 135 using mknod ("man mknod"), you
@@ -750,6 +751,28 @@ config RTC
           To compile this driver as a module, choose M here: the
           module will be called rtc.
 
+config JS_RTC
+        tristate "Enhanced Real Time Clock Support"
+        depends on SPARC32 && PCI
+        ---help---
+          If you say Y here and create a character special file /dev/rtc with
+          major number 10 and minor number 135 using mknod ("man mknod"), you
+          will get access to the real time clock (or hardware clock) built
+          into your computer.
+
+          Every PC has such a clock built in. It can be used to generate
+          signals from as low as 1Hz up to 8192Hz, and can also be used
+          as a 24 hour alarm. It reports status information via the file
+          /proc/driver/rtc and its behaviour is set by various ioctls on
+          /dev/rtc.
+
+          If you think you have a use for such a device (such as periodic data
+          sampling), then say Y here, and read <file:Documentation/rtc.txt>
+          for details.
+
+          To compile this driver as a module, choose M here: the
+          module will be called js-rtc.
+
 config SGI_DS1286
         tristate "SGI DS1286 RTC support"
         depends on SGI_IP22
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 2bc3a55ee407..d68ddbe70f73 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -108,6 +108,9 @@ obj-$(CONFIG_TCG_TPM)		+= tpm/
 
 obj-$(CONFIG_PS3_FLASH)         += ps3flash.o
 
+obj-$(CONFIG_JS_RTC)            += js-rtc.o
+js-rtc-y = rtc.o
+
 # Files generated that shall be removed upon make clean
 clean-files := consolemap_deftbl.c defkeymap.c
 
diff --git a/drivers/char/agp/Kconfig b/drivers/char/agp/Kconfig
index a9f9c48c2424..713533d8a86e 100644
--- a/drivers/char/agp/Kconfig
+++ b/drivers/char/agp/Kconfig
@@ -50,7 +50,7 @@ config AGP_ATI
 
 config AGP_AMD
         tristate "AMD Irongate, 761, and 762 chipset support"
-        depends on AGP && X86_32
+        depends on AGP && (X86_32 || ALPHA)
         help
           This option gives you AGP support for the GLX component of
           X on AMD Irongate, 761, and 762 chipsets.
diff --git a/drivers/char/agp/ati-agp.c b/drivers/char/agp/ati-agp.c
index 780e59e588ad..da7513d7b4e7 100644
--- a/drivers/char/agp/ati-agp.c
+++ b/drivers/char/agp/ati-agp.c
@@ -123,21 +123,16 @@ static int ati_create_gatt_pages(int nr_tables)
 
         for (i = 0; i < nr_tables; i++) {
                 entry = kzalloc(sizeof(struct ati_page_map), GFP_KERNEL);
+                tables[i] = entry;
                 if (entry == NULL) {
-                        while (i > 0) {
-                                kfree(tables[i-1]);
-                                i--;
-                        }
-                        kfree(tables);
                         retval = -ENOMEM;
                         break;
                 }
-                tables[i] = entry;
                 retval = ati_create_page_map(entry);
                 if (retval != 0)
                         break;
         }
-        ati_generic_private.num_tables = nr_tables;
+        ati_generic_private.num_tables = i;
         ati_generic_private.gatt_pages = tables;
 
         if (retval != 0)
diff --git a/drivers/char/agp/compat_ioctl.c b/drivers/char/agp/compat_ioctl.c
index fcb4b1bf0d4e..ecd4248861b9 100644
--- a/drivers/char/agp/compat_ioctl.c
+++ b/drivers/char/agp/compat_ioctl.c
@@ -28,6 +28,7 @@
 
 #include <linux/kernel.h>
 #include <linux/pci.h>
+#include <linux/fs.h>
 #include <linux/agpgart.h>
 #include <asm/uaccess.h>
 #include "agp.h"
diff --git a/drivers/char/agp/frontend.c b/drivers/char/agp/frontend.c
index c7ed617aa7ff..7791e98de51c 100644
--- a/drivers/char/agp/frontend.c
+++ b/drivers/char/agp/frontend.c
@@ -37,6 +37,7 @@
 #include <linux/agpgart.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
+#include <linux/fs.h>
 #include <linux/sched.h>
 #include <asm/uaccess.h>
 #include <asm/pgtable.h>
diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index d535c406b319..3db4f4076ed4 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -1170,7 +1170,6 @@ void *agp_generic_alloc_page(struct agp_bridge_data *bridge)
         map_page_into_agp(page);
 
         get_page(page);
-        SetPageLocked(page);
         atomic_inc(&agp_bridge->current_memory_agp);
         return page_address(page);
 }
@@ -1187,7 +1186,6 @@ void agp_generic_destroy_page(void *addr)
         page = virt_to_page(addr);
         unmap_page_from_agp(page);
         put_page(page);
-        unlock_page(page);
         free_page((unsigned long)addr);
         atomic_dec(&agp_bridge->current_memory_agp);
 }
diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index a1240603912c..294cdbf4d44d 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -20,7 +20,9 @@
 #define PCI_DEVICE_ID_INTEL_82965G_IG       0x29A2
 #define PCI_DEVICE_ID_INTEL_82965GM_HB      0x2A00
 #define PCI_DEVICE_ID_INTEL_82965GM_IG      0x2A02
+#define PCI_DEVICE_ID_INTEL_82965GME_HB     0x2A10
 #define PCI_DEVICE_ID_INTEL_82965GME_IG     0x2A12
+#define PCI_DEVICE_ID_INTEL_82945GME_HB     0x27AC
 #define PCI_DEVICE_ID_INTEL_82945GME_IG     0x27AE
 #define PCI_DEVICE_ID_INTEL_G33_HB          0x29C0
 #define PCI_DEVICE_ID_INTEL_G33_IG          0x29C2
@@ -33,7 +35,8 @@
                  agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82965G_1_HB || \
                  agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82965Q_HB || \
                  agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82965G_HB || \
-                 agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82965GM_HB)
+                 agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82965GM_HB || \
+                 agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82965GME_HB)
 
 #define IS_G33 (agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_G33_HB || \
                 agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_Q35_HB || \
@@ -213,7 +216,6 @@ static void *i8xx_alloc_pages(void)
         }
         global_flush_tlb();
         get_page(page);
-        SetPageLocked(page);
         atomic_inc(&agp_bridge->current_memory_agp);
         return page_address(page);
 }
@@ -229,7 +231,6 @@ static void i8xx_destroy_pages(void *addr)
         change_page_attr(page, 4, PAGE_KERNEL);
         global_flush_tlb();
         put_page(page);
-        unlock_page(page);
         __free_pages(page, 2);
         atomic_dec(&agp_bridge->current_memory_agp);
 }
@@ -527,6 +528,7 @@ static void intel_i830_init_gtt_entries(void)
                             agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82915GM_HB ||
                             agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82945G_HB ||
                             agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82945GM_HB ||
+                            agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82945GME_HB ||
                             IS_I965 || IS_G33)
                                 gtt_entries = MB(48) - KB(size);
                         else
@@ -538,6 +540,7 @@ static void intel_i830_init_gtt_entries(void)
                             agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82915GM_HB ||
                             agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82945G_HB ||
                             agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82945GM_HB ||
+                            agp_bridge->dev->device == PCI_DEVICE_ID_INTEL_82945GME_HB ||
                             IS_I965 || IS_G33)
                                 gtt_entries = MB(64) - KB(size);
                         else
@@ -1848,9 +1851,9 @@ static const struct intel_driver_description {
                 NULL, &intel_915_driver },
         { PCI_DEVICE_ID_INTEL_82945G_HB, PCI_DEVICE_ID_INTEL_82945G_IG, 0, "945G",
                 NULL, &intel_915_driver },
-        { PCI_DEVICE_ID_INTEL_82945GM_HB, PCI_DEVICE_ID_INTEL_82945GM_IG, 1, "945GM",
+        { PCI_DEVICE_ID_INTEL_82945GM_HB, PCI_DEVICE_ID_INTEL_82945GM_IG, 0, "945GM",
                 NULL, &intel_915_driver },
-        { PCI_DEVICE_ID_INTEL_82945GM_HB, PCI_DEVICE_ID_INTEL_82945GME_IG, 0, "945GME",
+        { PCI_DEVICE_ID_INTEL_82945GME_HB, PCI_DEVICE_ID_INTEL_82945GME_IG, 0, "945GME",
                 NULL, &intel_915_driver },
         { PCI_DEVICE_ID_INTEL_82946GZ_HB, PCI_DEVICE_ID_INTEL_82946GZ_IG, 0, "946GZ",
                 NULL, &intel_i965_driver },
@@ -1860,9 +1863,9 @@ static const struct intel_driver_description {
                 NULL, &intel_i965_driver },
         { PCI_DEVICE_ID_INTEL_82965G_HB, PCI_DEVICE_ID_INTEL_82965G_IG, 0, "965G",
                 NULL, &intel_i965_driver },
-        { PCI_DEVICE_ID_INTEL_82965GM_HB, PCI_DEVICE_ID_INTEL_82965GM_IG, 1, "965GM",
+        { PCI_DEVICE_ID_INTEL_82965GM_HB, PCI_DEVICE_ID_INTEL_82965GM_IG, 0, "965GM",
                 NULL, &intel_i965_driver },
-        { PCI_DEVICE_ID_INTEL_82965GM_HB, PCI_DEVICE_ID_INTEL_82965GME_IG, 0, "965GME/GLE",
+        { PCI_DEVICE_ID_INTEL_82965GME_HB, PCI_DEVICE_ID_INTEL_82965GME_IG, 0, "965GME/GLE",
                 NULL, &intel_i965_driver },
         { PCI_DEVICE_ID_INTEL_7505_0, 0, 0, "E7505", &intel_7505_driver, NULL },
         { PCI_DEVICE_ID_INTEL_7205_0, 0, 0, "E7205", &intel_7505_driver, NULL },
@@ -2051,11 +2054,13 @@ static struct pci_device_id agp_intel_pci_table[] = {
         ID(PCI_DEVICE_ID_INTEL_82915GM_HB),
         ID(PCI_DEVICE_ID_INTEL_82945G_HB),
         ID(PCI_DEVICE_ID_INTEL_82945GM_HB),
+        ID(PCI_DEVICE_ID_INTEL_82945GME_HB),
         ID(PCI_DEVICE_ID_INTEL_82946GZ_HB),
         ID(PCI_DEVICE_ID_INTEL_82965G_1_HB),
         ID(PCI_DEVICE_ID_INTEL_82965Q_HB),
         ID(PCI_DEVICE_ID_INTEL_82965G_HB),
         ID(PCI_DEVICE_ID_INTEL_82965GM_HB),
+        ID(PCI_DEVICE_ID_INTEL_82965GME_HB),
         ID(PCI_DEVICE_ID_INTEL_G33_HB),
         ID(PCI_DEVICE_ID_INTEL_Q35_HB),
         ID(PCI_DEVICE_ID_INTEL_Q33_HB),
diff --git a/drivers/char/agp/sgi-agp.c b/drivers/char/agp/sgi-agp.c
index cda608c42bea..98cf8abb3e57 100644
--- a/drivers/char/agp/sgi-agp.c
+++ b/drivers/char/agp/sgi-agp.c
@@ -51,7 +51,6 @@ static void *sgi_tioca_alloc_page(struct agp_bridge_data *bridge)
                 return NULL;
 
         get_page(page);
-        SetPageLocked(page);
         atomic_inc(&agp_bridge->current_memory_agp);
         return page_address(page);
 }
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index ba0e74ad74bb..77bf4aa217a8 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -73,7 +73,7 @@ static struct clocksource clocksource_hpet = {
         .name           = "hpet",
         .rating         = 250,
         .read           = read_hpet,
-        .mask           = 0xffffffffffffffff,
+        .mask           = CLOCKSOURCE_MASK(64),
         .mult           = 0, /*to be caluclated*/
         .shift          = 10,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
@@ -1007,9 +1007,15 @@ static int hpet_acpi_remove(struct acpi_device *device, int type)
         return -EINVAL;
 }
 
+static const struct acpi_device_id hpet_device_ids[] = {
+        {"PNP0103", 0},
+        {"", 0},
+};
+MODULE_DEVICE_TABLE(acpi, hpet_device_ids);
+
 static struct acpi_driver hpet_acpi_driver = {
         .name = "hpet",
-        .ids = "PNP0103",
+        .ids = hpet_device_ids,
         .ops = {
                 .add = hpet_acpi_add,
                 .remove = hpet_acpi_remove,
diff --git a/drivers/char/hvc_lguest.c b/drivers/char/hvc_lguest.c
index e7b889e404a7..feeccbaec438 100644
--- a/drivers/char/hvc_lguest.c
+++ b/drivers/char/hvc_lguest.c
@@ -1,6 +1,22 @@
-/* Simple console for lguest.
+/*D:300
+ * The Guest console driver
  *
- * Copyright (C) 2006 Rusty Russell, IBM Corporation
+ * This is a trivial console driver: we use lguest's DMA mechanism to send
+ * bytes out, and register a DMA buffer to receive bytes in.  It is assumed to
+ * be present and available from the very beginning of boot.
+ *
+ * Writing console drivers is one of the few remaining Dark Arts in Linux.
+ * Fortunately for us, the path of virtual consoles has been well-trodden by
+ * the PowerPC folks, who wrote "hvc_console.c" to generically support any
+ * virtual console.  We use that infrastructure which only requires us to write
+ * the basic put_chars and get_chars functions and call the right register
+ * functions.
+ :*/
+
+/*M:002 The console can be flooded: while the Guest is processing input the
+ * Host can send more.  Buffering in the Host could alleviate this, but it is a
+ * difficult problem in general. :*/
+/* Copyright (C) 2006 Rusty Russell, IBM Corporation
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -21,49 +37,81 @@
 #include <linux/lguest_bus.h>
 #include "hvc_console.h"
 
+/*D:340 This is our single console input buffer, with associated "struct
+ * lguest_dma" referring to it.  Note the 0-terminated length array, and the
+ * use of physical address for the buffer itself. */
 static char inbuf[256];
 static struct lguest_dma cons_input = { .used_len = 0,
                                         .addr[0] = __pa(inbuf),
                                         .len[0] = sizeof(inbuf),
                                         .len[1] = 0 };
 
+/*D:310 The put_chars() callback is pretty straightforward.
+ *
+ * First we put the pointer and length in a "struct lguest_dma": we only have
+ * one pointer, so we set the second length to 0.  Then we use SEND_DMA to send
+ * the data to (Host) buffers attached to the console key.  Usually a device's
+ * key is a physical address within the device's memory, but because the
+ * console device doesn't have any associated physical memory, we use the
+ * LGUEST_CONSOLE_DMA_KEY constant (aka 0). */
 static int put_chars(u32 vtermno, const char *buf, int count)
 {
         struct lguest_dma dma;
 
-        /* FIXME: what if it's over a page boundary? */
+        /* FIXME: DMA buffers in a "struct lguest_dma" are not allowed
+         * to go over page boundaries.  This never seems to happen,
+         * but if it did we'd need to fix this code. */
         dma.len[0] = count;
         dma.len[1] = 0;
         dma.addr[0] = __pa(buf);
 
         lguest_send_dma(LGUEST_CONSOLE_DMA_KEY, &dma);
+        /* We're expected to return the amount of data we wrote: all of it. */
         return count;
 }
 
+/*D:350 get_chars() is the callback from the hvc_console infrastructure when
+ * an interrupt is received.
+ *
+ * Firstly we see if our buffer has been filled: if not, we return.  The rest
+ * of the code deals with the fact that the hvc_console() infrastructure only
+ * asks us for 16 bytes at a time.  We keep a "cons_offset" variable for
+ * partially-read buffers. */
 static int get_chars(u32 vtermno, char *buf, int count)
 {
         static int cons_offset;
 
+        /* Nothing left to see here... */
         if (!cons_input.used_len)
                 return 0;
 
+        /* You want more than we have to give?  Well, try wanting less! */
         if (cons_input.used_len - cons_offset < count)
                 count = cons_input.used_len - cons_offset;
 
+        /* Copy across to their buffer and increment offset. */
         memcpy(buf, inbuf + cons_offset, count);
         cons_offset += count;
+
+        /* Finished?  Zero offset, and reset cons_input so Host will use it
+         * again. */
         if (cons_offset == cons_input.used_len) {
                 cons_offset = 0;
                 cons_input.used_len = 0;
         }
         return count;
 }
+/*:*/
 
 static struct hv_ops lguest_cons = {
         .get_chars = get_chars,
         .put_chars = put_chars,
 };
 
+/*D:320 Console drivers are initialized very early so boot messages can go
+ * out.  At this stage, the console is output-only.  Our driver checks we're a
+ * Guest, and if so hands hvc_instantiate() the console number (0), priority
+ * (0), and the struct hv_ops containing the put_chars() function. */
 static int __init cons_init(void)
 {
         if (strcmp(paravirt_ops.name, "lguest") != 0)
@@ -73,21 +121,46 @@ static int __init cons_init(void)
 }
 console_initcall(cons_init);
 
+/*D:370 To set up and manage our virtual console, we call hvc_alloc() and
+ * stash the result in the private pointer of the "struct lguest_device".
+ * Since we never remove the console device we never need this pointer again,
+ * but using ->private is considered good form, and you never know who's going
+ * to copy your driver.
+ *
+ * Once the console is set up, we bind our input buffer ready for input. */
 static int lguestcons_probe(struct lguest_device *lgdev)
 {
         int err;
 
+        /* The first argument of hvc_alloc() is the virtual console number, so
+         * we use zero.  The second argument is the interrupt number.
+         *
+         * The third argument is a "struct hv_ops" containing the put_chars()
+         * and get_chars() pointers.  The final argument is the output buffer
+         * size: we use 256 and expect the Host to have room for us to send
+         * that much. */
         lgdev->private = hvc_alloc(0, lgdev_irq(lgdev), &lguest_cons, 256);
         if (IS_ERR(lgdev->private))
                 return PTR_ERR(lgdev->private);
 
+        /* We bind a single DMA buffer at key LGUEST_CONSOLE_DMA_KEY.
+         * "cons_input" is that statically-initialized global DMA buffer we saw
+         * above, and we also give the interrupt we want. */
         err = lguest_bind_dma(LGUEST_CONSOLE_DMA_KEY, &cons_input, 1,
                               lgdev_irq(lgdev));
         if (err)
                 printk("lguest console: failed to bind buffer.\n");
         return err;
 }
+/* Note the use of lgdev_irq() for the interrupt number.  We tell hvc_alloc()
+ * to expect input when this interrupt is triggered, and then tell
+ * lguest_bind_dma() that is the interrupt to send us when input comes in. */
 
+/*D:360 From now on the console driver follows standard Guest driver form:
+ * register_lguest_driver() registers the device type and probe function, and
+ * the probe function sets up the device.
+ *
+ * The standard "struct lguest_driver": */
 static struct lguest_driver lguestcons_drv = {
         .name = "lguestcons",
         .owner = THIS_MODULE,
@@ -95,6 +168,7 @@ static struct lguest_driver lguestcons_drv = {
         .probe = lguestcons_probe,
 };
 
+/* The standard init function */
 static int __init hvc_lguest_init(void)
 {
         return register_lguest_driver(&lguestcons_drv);
diff --git a/drivers/char/ip2/ip2main.c b/drivers/char/ip2/ip2main.c
index 6005b5225772..8d74b8745e60 100644
--- a/drivers/char/ip2/ip2main.c
+++ b/drivers/char/ip2/ip2main.c
@@ -500,7 +500,6 @@ ip2_loadmain(int *iop, int *irqp, unsigned char *firmware, int firmsize)
 {
         int i, j, box;
         int err = 0;
-        int status = 0;
         static int loaded;
         i2eBordStrPtr pB = NULL;
         int rc = -1;
@@ -588,6 +587,8 @@ ip2_loadmain(int *iop, int *irqp, unsigned char *firmware, int firmsize)
                 case PCI:
 #ifdef CONFIG_PCI
                         {
+                                int status;
+
                                 pci_dev_i = pci_get_device(PCI_VENDOR_ID_COMPUTONE,
                                                           PCI_DEVICE_ID_COMPUTONE_IP2EX, pci_dev_i);
                                 if (pci_dev_i != NULL) {
diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 4edfdda0cf99..96d2f9ee42d6 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -2050,6 +2050,7 @@ static __devinit void try_init_dmi(struct dmi_ipmi_data *ipmi_data)
                 info->si_type = SI_BT;
                 break;
         default:
+                kfree(info);
                 return;
         }
 
diff --git a/drivers/char/mmtimer.c b/drivers/char/mmtimer.c
index 6e55cfb9c65a..e60a74c66e3d 100644
--- a/drivers/char/mmtimer.c
+++ b/drivers/char/mmtimer.c
@@ -25,6 +25,7 @@
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/mm.h>
+#include <linux/fs.h>
 #include <linux/mmtimer.h>
 #include <linux/miscdevice.h>
 #include <linux/posix-timers.h>
diff --git a/drivers/char/mspec.c b/drivers/char/mspec.c
index c716ef0dd370..c08a4152ee8f 100644
--- a/drivers/char/mspec.c
+++ b/drivers/char/mspec.c
@@ -38,6 +38,7 @@
 #include <linux/miscdevice.h>
 #include <linux/spinlock.h>
 #include <linux/mm.h>
+#include <linux/fs.h>
 #include <linux/vmalloc.h>
 #include <linux/string.h>
 #include <linux/slab.h>
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 372a37e25620..bbb7f1292665 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -1,5 +1,5 @@
 /*
- * $Id: synclink_gt.c,v 4.36 2006/08/28 20:47:14 paulkf Exp $
+ * $Id: synclink_gt.c,v 4.50 2007/07/25 19:29:25 paulkf Exp $
  *
  * Device driver for Microgate SyncLink GT serial adapters.
  *
@@ -93,7 +93,7 @@
  * module identification
  */
 static char *driver_name     = "SyncLink GT";
-static char *driver_version  = "$Revision: 4.36 $";
+static char *driver_version  = "$Revision: 4.50 $";
 static char *tty_driver_name = "synclink_gt";
 static char *tty_dev_prefix  = "ttySLG";
 MODULE_LICENSE("GPL");
@@ -477,6 +477,7 @@ static void tx_set_idle(struct slgt_info *info);
 static unsigned int free_tbuf_count(struct slgt_info *info);
 static void reset_tbufs(struct slgt_info *info);
 static void tdma_reset(struct slgt_info *info);
+static void tdma_start(struct slgt_info *info);
 static void tx_load(struct slgt_info *info, const char *buf, unsigned int count);
 
 static void get_signals(struct slgt_info *info);
@@ -904,6 +905,8 @@ start:
                 spin_lock_irqsave(&info->lock,flags);
                 if (!info->tx_active)
                         tx_start(info);
+                else
+                        tdma_start(info);
                 spin_unlock_irqrestore(&info->lock,flags);
         }
 
@@ -3871,44 +3874,58 @@ static void tx_start(struct slgt_info *info)
                         slgt_irq_on(info, IRQ_TXUNDER + IRQ_TXIDLE);
                         /* clear tx idle and underrun status bits */
                         wr_reg16(info, SSR, (unsigned short)(IRQ_TXIDLE + IRQ_TXUNDER));
-
-                        if (!(rd_reg32(info, TDCSR) & BIT0)) {
-                                /* tx DMA stopped, restart tx DMA */
-                                tdma_reset(info);
-                                /* set 1st descriptor address */
-                                wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc);
-                                switch(info->params.mode) {
-                                case MGSL_MODE_RAW:
-                                case MGSL_MODE_MONOSYNC:
-                                case MGSL_MODE_BISYNC:
-                                        wr_reg32(info, TDCSR, BIT2 + BIT0); /* IRQ + DMA enable */
-                                        break;
-                                default:
-                                        wr_reg32(info, TDCSR, BIT0); /* DMA enable */
-                                }
-                        }
-
                         if (info->params.mode == MGSL_MODE_HDLC)
                                 mod_timer(&info->tx_timer, jiffies +
                                                 msecs_to_jiffies(5000));
                 } else {
-                        tdma_reset(info);
-                        /* set 1st descriptor address */
-                        wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc);
-
                         slgt_irq_off(info, IRQ_TXDATA);
                         slgt_irq_on(info, IRQ_TXIDLE);
                         /* clear tx idle status bit */
                         wr_reg16(info, SSR, IRQ_TXIDLE);
-
-                        /* enable tx DMA */
-                        wr_reg32(info, TDCSR, BIT0);
                 }
-
+                tdma_start(info);
                 info->tx_active = 1;
         }
 }
 
+/*
+ * start transmit DMA if inactive and there are unsent buffers
+ */
+static void tdma_start(struct slgt_info *info)
+{
+        unsigned int i;
+
+        if (rd_reg32(info, TDCSR) & BIT0)
+                return;
+
+        /* transmit DMA inactive, check for unsent buffers */
+        i = info->tbuf_start;
+        while (!desc_count(info->tbufs[i])) {
+                if (++i == info->tbuf_count)
+                        i = 0;
+                if (i == info->tbuf_current)
+                        return;
+        }
+        info->tbuf_start = i;
+
+        /* there are unsent buffers, start transmit DMA */
+
+        /* reset needed if previous error condition */
+        tdma_reset(info);
+
+        /* set 1st descriptor address */
+        wr_reg32(info, TDDAR, info->tbufs[info->tbuf_start].pdesc);
+        switch(info->params.mode) {
+        case MGSL_MODE_RAW:
+        case MGSL_MODE_MONOSYNC:
+        case MGSL_MODE_BISYNC:
+                wr_reg32(info, TDCSR, BIT2 + BIT0); /* IRQ + DMA enable */
+                break;
+        default:
+                wr_reg32(info, TDCSR, BIT0); /* DMA enable */
+        }
+}
+
 static void tx_stop(struct slgt_info *info)
 {
         unsigned short val;
@@ -4642,8 +4659,8 @@ static unsigned int free_tbuf_count(struct slgt_info *info)
                         i=0;
         } while (i != info->tbuf_current);
 
-        /* last buffer with zero count may be in use, assume it is */
-        if (count)
+        /* if tx DMA active, last zero count buffer is in use */
+        if (count && (rd_reg32(info, TDCSR) & BIT0))
                 --count;
 
         return count;