[PATCH 2.6.38.1] pata_it821x: Add module param to force UDMA on Vortex86SX

[igor]

This patch adds parameter 'it8212_rdc11_force_udma' to 'pata_it821x' 
module,
which allows users to force UDMA mode on RDC11/Vortex86SX embedded 
devices.

---
UDMA is disabled by default due to some CRC errors, which i cannot 
observe when
using CompactFlash card with patched driver.

May be there are errors with pure IDE devices or with older revisions 
of Vortex86SX
boards, i do no know. But for my device i have 2x improvement in I/O 
speed when
enabling UDMA/33 instead of MWDMA, so i think this parameter would be 
useful.

Also fix to initialize default value for parameter 'noraid'.

--- b/drivers/ata/pata_it821x.c 2011-03-23 23:04:47.000000000 +0300
+++ a/drivers/ata/pata_it821x.c 2011-03-26 15:10:49.608952573 +0300
@@ -111,7 +111,8 @@ struct it821x_dev
  *     device.
  */

-static int it8212_noraid;
+static int it8212_noraid = 0;
+static int it8212_rdc11_force_udma = 0;

 /**
  *     it821x_program  -       program the PIO/MWDMA registers
@@ -913,7 +914,7 @@ static int it821x_init_one(struct pci_de

        if (pdev->vendor == PCI_VENDOR_ID_RDC) {
                /* Deal with Vortex86SX */
-               if (pdev->revision == 0x11)
+               if (pdev->revision == 0x11 && !it8212_rdc11_force_udma)
                        ppi[0] = &info_rdc_11;
                else
                        ppi[0] = &info_rdc;
@@ -988,9 +989,12 @@ MODULE_LICENSE("GPL");
 MODULE_DEVICE_TABLE(pci, it821x);
 MODULE_VERSION(DRV_VERSION);

-
 module_param_named(noraid, it8212_noraid, int, S_IRUGO);
 MODULE_PARM_DESC(noraid, "Force card into bypass mode");

+module_param_named(rdc11_force_udma, it8212_rdc11_force_udma, int, 
S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(rdc11_force_udma, "Force enable UDMA mode 
RDC11/Vortex86SX boards."
+       " Use with caution");
+
 module_init(it821x_init);
 module_exit(it821x_exit);

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