ide: DMA reporting and validity checking fixes (take 3)

* ide_xfer_verbose() fixups:
  - beautify returned mode names
  - fix PIO5 reporting
  - make it return 'const char *'

* Change printk() level from KERN_DEBUG to KERN_INFO in ide_find_dma_mode().

* Add ide_id_dma_bug() helper based on ide_dma_verbose() to check for invalid
  DMA info in identify block.

* Use ide_id_dma_bug() in ide_tune_dma() and ide_driveid_update().

  As a result DMA won't be tuned or will be disabled after tuning if device
  reports inconsistent info about enabled DMA mode (ide_dma_verbose() does the
  same checks while the IDE device is probed by ide-{cd,disk} device driver).

* Remove no longer needed ide_dma_verbose().

This patch should fix the following problem with out-of-sync IDE messages
reported by Nick Warne:

       hdd: ATAPI 48X DVD-ROM DVD-R-RAM CD-R/RW drive, 2048kB Cache<7>hdd:
       skipping word 93 validity check
        , UDMA(66)

and later debugged by Mark Lord to be caused by:

        ide_dma_verbose()
                printk( ... "2048kB Cache");
        eighty_ninty_three()
                printk(KERN_DEBUG "%s: skipping word 93 validity check\n");
        ide_dma_verbose()
                printk(", UDMA(66)"

Please note that as a result ide-{cd,disk} device drivers won't report the
DMA speed used but this is intended since now DMA mode being used is always
reported by IDE core code.

v2:
* fixes suggested by Randy:
  - use KERN_CONT for printk()-s in ide-{cd,disk}.c
  - don't remove argument name from ide_xfer_verbose() declaration

v3:
* Remove incorrect check for (id->field_valid & 1) from ide_id_dma_bug()
  (spotted by Sergei).

* "XFER SLOW" -> "PIO SLOW" in ide_xfer_verbose() (suggested by Sergei).

* Fix ide_find_dma_mode() to report the correct mode ('mode' after being
  limited by 'req_mode').

Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Nick Warne <nick@ukfsn.org>
Cc: Mark Lord <lkml@rtr.ca>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 29 insertions, 26 deletions

diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index 1609b8604f56..062d3bcb2471 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -29,41 +29,44 @@
  *      Add common non I/O op stuff here. Make sure it has proper
  *      kernel-doc function headers or your patch will be rejected
  */
- 
+
+static const char *udma_str[] =
+         { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
+           "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
+static const char *mwdma_str[] =
+        { "MWDMA0", "MWDMA1", "MWDMA2" };
+static const char *swdma_str[] =
+        { "SWDMA0", "SWDMA1", "SWDMA2" };
+static const char *pio_str[] =
+        { "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5" };
 
 /**
  *      ide_xfer_verbose        -       return IDE mode names
- *      @xfer_rate: rate to name
+ *      @mode: transfer mode
  *
  *      Returns a constant string giving the name of the mode
  *      requested.
  */
 
-char *ide_xfer_verbose (u8 xfer_rate)
+const char *ide_xfer_verbose(u8 mode)
 {
-        switch(xfer_rate) {
-                case XFER_UDMA_7:       return("UDMA 7");
-                case XFER_UDMA_6:       return("UDMA 6");
-                case XFER_UDMA_5:       return("UDMA 5");
-                case XFER_UDMA_4:       return("UDMA 4");
-                case XFER_UDMA_3:       return("UDMA 3");
-                case XFER_UDMA_2:       return("UDMA 2");
-                case XFER_UDMA_1:       return("UDMA 1");
-                case XFER_UDMA_0:       return("UDMA 0");
-                case XFER_MW_DMA_2:     return("MW DMA 2");
-                case XFER_MW_DMA_1:     return("MW DMA 1");
-                case XFER_MW_DMA_0:     return("MW DMA 0");
-                case XFER_SW_DMA_2:     return("SW DMA 2");
-                case XFER_SW_DMA_1:     return("SW DMA 1");
-                case XFER_SW_DMA_0:     return("SW DMA 0");
-                case XFER_PIO_4:        return("PIO 4");
-                case XFER_PIO_3:        return("PIO 3");
-                case XFER_PIO_2:        return("PIO 2");
-                case XFER_PIO_1:        return("PIO 1");
-                case XFER_PIO_0:        return("PIO 0");
-                case XFER_PIO_SLOW:     return("PIO SLOW");
-                default:                return("XFER ERROR");
-        }
+        const char *s;
+        u8 i = mode & 0xf;
+
+        if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
+                s = udma_str[i];
+        else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_2)
+                s = mwdma_str[i];
+        else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
+                s = swdma_str[i];
+        else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_5)
+                s = pio_str[i & 0x7];
+        else if (mode == XFER_PIO_SLOW)
+                s = "PIO SLOW";
+        else
+                s = "XFER ERROR";
+
+        return s;
 }
 
 EXPORT_SYMBOL(ide_xfer_verbose);