PATCH: make the sl82c105 work again

From: Alan Cox (alan@lxorguk.ukuu.org.uk)
Date: Tue Feb 18 2003 - 13:34:29 EST


diff -u --new-file --recursive --exclude-from /usr/src/exclude linux-2.5.61/drivers/ide/pci/sl82c105.c linux-2.5.61-ac2/drivers/ide/pci/sl82c105.c
--- linux-2.5.61/drivers/ide/pci/sl82c105.c 2003-02-10 18:38:17.000000000 +0000
+++ linux-2.5.61-ac2/drivers/ide/pci/sl82c105.c 2003-02-18 18:06:19.000000000 +0000
@@ -1,5 +1,5 @@
 /*
- * linux/drivers/ide/sl82c105.c
+ * linux/drivers/ide/pci/sl82c105.c
  *
  * SL82C105/Winbond 553 IDE driver
  *
@@ -7,6 +7,10 @@
  *
  * Drive tuning added from Rebel.com's kernel sources
  * -- Russell King (15/11/98) linux@arm.linux.org.uk
+ *
+ * Merge in Russell's HW workarounds, fix various problems
+ * with the timing registers setup.
+ * -- Benjamin Herrenschmidt (01/11/03) benh@kernel.crashing.org
  */
 
 #include <linux/config.h>
@@ -28,6 +32,24 @@
 #include "ide_modes.h"
 #include "sl82c105.h"
 
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(arg) printk arg
+#else
+#define DBG(fmt,...)
+#endif
+/*
+ * SL82C105 PCI config register 0x40 bits.
+ */
+#define CTRL_IDE_IRQB (1 << 30)
+#define CTRL_IDE_IRQA (1 << 28)
+#define CTRL_LEGIRQ (1 << 11)
+#define CTRL_P1F16 (1 << 5)
+#define CTRL_P1EN (1 << 4)
+#define CTRL_P0F16 (1 << 1)
+#define CTRL_P0EN (1 << 0)
+
 /*
  * Convert a PIO mode and cycle time to the required on/off
  * times for the interface. This has protection against run-away
@@ -57,7 +79,7 @@
 /*
  * Configure the drive and chipset for PIO
  */
-static void config_for_pio(ide_drive_t *drive, int pio, int report)
+static void config_for_pio(ide_drive_t *drive, int pio, int report, int chipset_only)
 {
         ide_hwif_t *hwif = HWIF(drive);
         struct pci_dev *dev = hwif->pci_dev;
@@ -65,14 +87,20 @@
         u16 drv_ctrl = 0x909;
         unsigned int xfer_mode, reg;
 
+ DBG(("config_for_pio(drive:%s, pio:%d, report:%d, chipset_only:%d)\n",
+ drive->name, pio, report, chipset_only));
+
         reg = (hwif->channel ? 0x4c : 0x44) + (drive->select.b.unit ? 4 : 0);
 
         pio = ide_get_best_pio_mode(drive, pio, 5, &p);
 
         xfer_mode = XFER_PIO_0 + pio;
 
- if (ide_config_drive_speed(drive, xfer_mode) == 0)
+ if (chipset_only || ide_config_drive_speed(drive, xfer_mode) == 0) {
                 drv_ctrl = get_timing_sl82c105(&p);
+ drive->pio_speed = xfer_mode;
+ } else
+ drive->pio_speed = XFER_PIO_0;
 
         if (drive->using_dma == 0) {
                 /*
@@ -96,15 +124,16 @@
 {
         ide_hwif_t *hwif = HWIF(drive);
         struct pci_dev *dev = hwif->pci_dev;
- u16 drv_ctrl = 0x909;
         unsigned int reg;
 
+ DBG(("config_for_dma(drive:%s)\n", drive->name));
+
         reg = (hwif->channel ? 0x4c : 0x44) + (drive->select.b.unit ? 4 : 0);
 
- if (ide_config_drive_speed(drive, XFER_MW_DMA_2) == 0)
- drv_ctrl = 0x0240;
+ if (ide_config_drive_speed(drive, XFER_MW_DMA_2) != 0)
+ return 1;
 
- pci_write_config_word(dev, reg, drv_ctrl);
+ pci_write_config_word(dev, reg, 0x0240);
 
         return 0;
 }
@@ -117,6 +146,9 @@
 static int sl82c105_check_drive (ide_drive_t *drive)
 {
         ide_hwif_t *hwif = HWIF(drive);
+
+ DBG(("sl82c105_check_drive(drive:%s)\n", drive->name));
+
         do {
                 struct hd_driveid *id = drive->id;
 
@@ -143,34 +175,188 @@
         return hwif->ide_dma_off_quietly(drive);
 }
 
+/*
+ * The SL82C105 holds off all IDE interrupts while in DMA mode until
+ * all DMA activity is completed. Sometimes this causes problems (eg,
+ * when the drive wants to report an error condition).
+ *
+ * 0x7e is a "chip testing" register. Bit 2 resets the DMA controller
+ * state machine. We need to kick this to work around various bugs.
+ */
+static inline void sl82c105_reset_host(struct pci_dev *dev)
+{
+ u16 val;
+
+ pci_read_config_word(dev, 0x7e, &val);
+ pci_write_config_word(dev, 0x7e, val | (1 << 2));
+ pci_write_config_word(dev, 0x7e, val & ~(1 << 2));
+}
+
+/*
+ * If we get an IRQ timeout, it might be that the DMA state machine
+ * got confused. Fix from Todd Inglett. Details from Winbond.
+ *
+ * This function is called when the IDE timer expires, the drive
+ * indicates that it is READY, and we were waiting for DMA to complete.
+ */
+static int sl82c105_ide_dma_lost_irq(ide_drive_t *drive)
+{
+ ide_hwif_t *hwif = HWIF(drive);
+ struct pci_dev *dev = hwif->pci_dev;
+ u32 val, mask = hwif->channel ? CTRL_IDE_IRQB : CTRL_IDE_IRQA;
+ unsigned long dma_base = hwif->dma_base;
+
+ printk("sl82c105: lost IRQ: resetting host\n");
+
+ /*
+ * Check the raw interrupt from the drive.
+ */
+ pci_read_config_dword(dev, 0x40, &val);
+ if (val & mask)
+ printk("sl82c105: drive was requesting IRQ, but host lost it\n");
+
+ /*
+ * Was DMA enabled? If so, disable it - we're resetting the
+ * host. The IDE layer will be handling the drive for us.
+ */
+ val = hwif->INB(dma_base);
+ if (val & 1) {
+ outb(val & ~1, dma_base);
+ printk("sl82c105: DMA was enabled\n");
+ }
+
+ sl82c105_reset_host(dev);
+
+ /* ide_dmaproc would return 1, so we do as well */
+ return 1;
+}
+
+/*
+ * ATAPI devices can cause the SL82C105 DMA state machine to go gaga.
+ * Winbond recommend that the DMA state machine is reset prior to
+ * setting the bus master DMA enable bit.
+ *
+ * The generic IDE core will have disabled the BMEN bit before this
+ * function is called.
+ */
+static int sl82c105_ide_dma_begin(ide_drive_t *drive)
+{
+ ide_hwif_t *hwif = HWIF(drive);
+ struct pci_dev *dev = hwif->pci_dev;
+
+// DBG(("sl82c105_ide_dma_begin(drive:%s)\n", drive->name));
+
+ sl82c105_reset_host(dev);
+ return __ide_dma_begin(drive);
+}
+
+static int sl82c105_ide_dma_timeout(ide_drive_t *drive)
+{
+ ide_hwif_t *hwif = HWIF(drive);
+ struct pci_dev *dev = hwif->pci_dev;
+
+ DBG(("sl82c105_ide_dma_timeout(drive:%s)\n", drive->name));
+
+ sl82c105_reset_host(dev);
+ return __ide_dma_timeout(drive);
+}
+
 static int sl82c105_ide_dma_on (ide_drive_t *drive)
 {
+ DBG(("sl82c105_ide_dma_on(drive:%s)\n", drive->name));
+
         if (config_for_dma(drive)) {
- config_for_pio(drive, 4, 0);
+ config_for_pio(drive, 4, 0, 0);
                 return HWIF(drive)->ide_dma_off_quietly(drive);
         }
+ printk(KERN_INFO "%s: DMA enabled\n", drive->name);
         return __ide_dma_on(drive);
 }
 
 static int sl82c105_ide_dma_off (ide_drive_t *drive)
 {
- config_for_pio(drive, 4, 0);
- return __ide_dma_off(drive);
+ u8 speed = XFER_PIO_0;
+ int rc;
+
+ DBG(("sl82c105_ide_dma_off(drive:%s)\n", drive->name));
+
+ rc = __ide_dma_off(drive);
+ if (drive->pio_speed)
+ speed = drive->pio_speed - XFER_PIO_0;
+ config_for_pio(drive, speed, 0, 1);
+ drive->current_speed = drive->pio_speed;
+
+ return rc;
 }
 
 static int sl82c105_ide_dma_off_quietly (ide_drive_t *drive)
 {
- config_for_pio(drive, 4, 0);
- return __ide_dma_off_quietly(drive);
+ u8 speed = XFER_PIO_0;
+ int rc;
+
+ DBG(("sl82c105_ide_dma_off_quietly(drive:%s)\n", drive->name));
+
+ rc = __ide_dma_off_quietly(drive);
+ if (drive->pio_speed)
+ speed = drive->pio_speed - XFER_PIO_0;
+ config_for_pio(drive, speed, 0, 1);
+ drive->current_speed = drive->pio_speed;
+
+ return rc;
+}
+
+/*
+ * Ok, that is nasty, but we must make sure the DMA timings
+ * won't be used for a PIO access. The solution here is
+ * to make sure the 16 bits mode is diabled on the channel
+ * when DMA is enabled, thus causing the chip to use PIO0
+ * timings for those operations.
+ */
+static void sl82c105_selectproc(ide_drive_t *drive)
+{
+ ide_hwif_t *hwif = HWIF(drive);
+ struct pci_dev *dev = hwif->pci_dev;
+ u32 val, old, mask;
+
+ //DBG(("sl82c105_selectproc(drive:%s)\n", drive->name));
+
+ mask = hwif->channel ? CTRL_P1F16 : CTRL_P0F16;
+ old = val = *((u32 *)&hwif->hwif_data);
+ if (drive->using_dma)
+ val &= ~mask;
+ else
+ val |= mask;
+ if (old != val) {
+ pci_write_config_dword(dev, 0x40, val);
+ *((u32 *)&hwif->hwif_data) = val;
+ }
 }
 
 /*
+ * ATA reset will clear the 16 bits mode in the control
+ * register, we need to update our cache
+ */
+static void sl82c105_resetproc(ide_drive_t *drive)
+{
+ ide_hwif_t *hwif = HWIF(drive);
+ struct pci_dev *dev = hwif->pci_dev;
+ u32 val;
+
+ DBG(("sl82c105_resetproc(drive:%s)\n", drive->name));
+
+ pci_read_config_dword(dev, 0x40, &val);
+ *((u32 *)&hwif->hwif_data) = val;
+}
+
+/*
  * We only deal with PIO mode here - DMA mode 'using_dma' is not
  * initialised at the point that this function is called.
  */
 static void tune_sl82c105(ide_drive_t *drive, u8 pio)
 {
- config_for_pio(drive, pio, 1);
+ DBG(("tune_sl82c105(drive:%s)\n", drive->name));
+
+ config_for_pio(drive, pio, 1, 0);
 
         /*
          * We support 32-bit I/O on this interface, and it
@@ -189,16 +375,20 @@
         struct pci_dev *bridge;
         u8 rev;
 
- bridge = pci_find_device(PCI_VENDOR_ID_WINBOND, PCI_DEVICE_ID_WINBOND_83C553, NULL);
-
         /*
- * If we are part of a Winbond 553
+ * The bridge should be part of the same device, but function 0.
          */
- if (!bridge || bridge->class >> 8 != PCI_CLASS_BRIDGE_ISA)
+ bridge = pci_find_slot(dev->bus->number,
+ PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
+ if (!bridge)
                 return -1;
 
- if (bridge->bus != dev->bus ||
- PCI_SLOT(bridge->devfn) != PCI_SLOT(dev->devfn))
+ /*
+ * Make sure it is a Winbond 553 and is an ISA bridge.
+ */
+ if (bridge->vendor != PCI_VENDOR_ID_WINBOND ||
+ bridge->device != PCI_DEVICE_ID_WINBOND_83C553 ||
+ bridge->class >> 8 != PCI_CLASS_BRIDGE_ISA)
                 return -1;
 
         /*
@@ -211,16 +401,21 @@
 
 /*
  * Enable the PCI device
+ *
+ * --BenH: It's arch fixup code that should enable channels that
+ * have not been enabled by firmware. I decided we can still enable
+ * channel 0 here at least, but channel 1 has to be enabled by
+ * firmware or arch code. We still set both to 16 bits mode.
  */
 static unsigned int __init init_chipset_sl82c105(struct pci_dev *dev, const char *msg)
 {
- u8 ctrl_stat;
+ u32 val;
 
- /*
- * Enable the ports
- */
- pci_read_config_byte(dev, 0x40, &ctrl_stat);
- pci_write_config_byte(dev, 0x40, ctrl_stat | 0x33);
+ DBG(("init_chipset_sl82c105()\n"));
+
+ pci_read_config_dword(dev, 0x40, &val);
+ val |= CTRL_P0EN | CTRL_P0F16 | CTRL_P1F16;
+ pci_write_config_dword(dev, 0x40, val);
 
         return dev->irq;
 }
@@ -230,6 +425,8 @@
         unsigned int rev;
         u8 dma_state;
 
+ DBG(("init_dma_sl82c105(hwif: ide%d, dma_base: 0x%08x)\n", hwif->index, dma_base));
+
         hwif->autodma = 0;
 
         if (!dma_base)
@@ -238,8 +435,6 @@
         dma_state = hwif->INB(dma_base + 2);
         rev = sl82c105_bridge_revision(hwif->pci_dev);
         if (rev <= 5) {
- hwif->drives[0].autotune = 1;
- hwif->drives[1].autotune = 1;
                 printk(" %s: Winbond 553 bridge revision %d, BM-DMA disabled\n",
                        hwif->name, rev);
                 dma_state &= ~0x60;
@@ -259,8 +454,28 @@
 
 static void __init init_hwif_sl82c105(ide_hwif_t *hwif)
 {
- hwif->tuneproc = tune_sl82c105;
+ struct pci_dev *dev = hwif->pci_dev;
+ u32 val;
+
+ DBG(("init_hwif_sl82c105(hwif: ide%d)\n", hwif->index));
 
+ hwif->tuneproc = tune_sl82c105;
+ hwif->selectproc = sl82c105_selectproc;
+ hwif->resetproc = sl82c105_resetproc;
+
+ /* Default to PIO 0 for fallback unless tuned otherwise,
+ * we always autotune PIO, this is done before DMA is
+ * checked, so there is no risk of accidentally disabling
+ * DMA
+ */
+ hwif->drives[0].pio_speed = XFER_PIO_0;
+ hwif->drives[0].autotune = 1;
+ hwif->drives[1].pio_speed = XFER_PIO_1;
+ hwif->drives[1].autotune = 1;
+
+ pci_read_config_dword(dev, 0x40, &val);
+ *((u32 *)&hwif->hwif_data) = val;
+
         if (!hwif->dma_base)
                 return;
 
@@ -273,6 +488,10 @@
         hwif->ide_dma_on = &sl82c105_ide_dma_on;
         hwif->ide_dma_off = &sl82c105_ide_dma_off;
         hwif->ide_dma_off_quietly = &sl82c105_ide_dma_off_quietly;
+ hwif->ide_dma_lostirq = &sl82c105_ide_dma_lost_irq;
+ hwif->ide_dma_begin = &sl82c105_ide_dma_begin;
+ hwif->ide_dma_timeout = &sl82c105_ide_dma_timeout;
+
         if (!noautodma)
                 hwif->autodma = 1;
         hwif->drives[0].autodma = hwif->autodma;
-
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This archive was generated by hypermail 2b29 : Sun Feb 23 2003 - 22:00:22 EST