Alexander Sabourenkov wrote:
Hello.
I have ported the workaround for the hardware bug that causes data
corruption on Promise SATA300 TX4 cards to RELENG_7.
Bug description:
SATA300 TX4 hardware chokes if last PRD entry (in a dma transfer) is
larger than 164 bytes. This was found while analysing vendor-supplied
linux driver.
Workaround:
Split trailing PRD entry if it's larger that 164 bytes.
Two supplied patches do fix problem on my machine.
There is, however, a style problem with them. It seems like PRD entry
count is limited at 256. I have not found a good way to guarantee that
one entry is always available to do the split, thus the ugly solution of
patching ata-dma.c.
Good catch!
However from my quick glimpse at the Promise sources the limit seems to
be 32 Dwords ie 32*4 = 128bytes.
I'll investigate further and ask Promise for the gory details, stay tuned...
I dont think the PRD count limitation is a real problem, I've newer seen
that long a list and IIRC we newer do more than 64K transfers in one go
(yet).
Anyhow I need to get checks in for that not just here...
Give me a few days and I'll get this figured out for 7-rel...
-Søren
Patches, patched and original files are at http://lxnt.info/tx4/freebsd/.
--- ata-chipset.c.orig 2007-11-02 01:05:49.000000000 +0300
+++ ata-chipset.c 2007-11-02 01:05:49.000000000 +0300
@@ -142,6 +142,7 @@
static int ata_promise_mio_command(struct ata_request *request);
static void ata_promise_mio_reset(device_t dev);
static void ata_promise_mio_dmainit(device_t dev);
+static void ata_promise_mio_dmasetprd(void *xsc, bus_dma_segment_t
*segs, int nsegs, int error);
static void ata_promise_mio_setmode(device_t dev, int mode);
static void ata_promise_sx4_intr(void *data);
static int ata_promise_sx4_command(struct ata_request *request);
@@ -185,7 +186,6 @@
static int ata_check_80pin(device_t dev, int mode);
static int ata_mode2idx(int mode);
-
/*
* generic ATA support functions
*/
@@ -3759,8 +3759,44 @@
static void
ata_promise_mio_dmainit(device_t dev)
{
+ struct ata_channel *ch = device_get_softc(dev);
+
/* note start and stop are not used here */
ata_dmainit(dev);
+
+ if (ch->dma)
+ ch->dma->setprd = ata_promise_mio_dmasetprd;
+}
+
+static void
+ata_promise_mio_dmasetprd(void *xsc, bus_dma_segment_t *segs, int
nsegs, int error)
+{
+ #define PDC_MAXLASTSGSIZE 41*4
+ struct ata_dmasetprd_args *args = xsc;
+ struct ata_dma_prdentry *prd = args->dmatab;
+ int i;
+
+ if ((args->error = error))
+ return;
+
+ for (i = 0; i < nsegs; i++) {
+ prd[i].addr = htole32(segs[i].ds_addr);
+ prd[i].count = htole32(segs[i].ds_len);
+ }
+
+ if (segs[i - 1].ds_len > PDC_MAXLASTSGSIZE) {
+ /*
+ printf("splitting trailing PRD of %ld (limit %d)\n", segs[i -
1].ds_len, PDC_MAXLASTSGSIZE);
+ */
+ prd[i - 1].count = htole32(segs[i - 1].ds_len - PDC_MAXLASTSGSIZE);
+ prd[i].count = htole32(PDC_MAXLASTSGSIZE);
+ prd[i].addr = htole32(segs[i - 1].ds_addr + PDC_MAXLASTSGSIZE);
+ i ++;
+ nsegs ++;
+ }
+
+ prd[i - 1].count |= htole32(ATA_DMA_EOT);
+ args->nsegs = nsegs;
}
static void
--- ata-dma.c.orig 2007-11-02 01:05:53.000000000 +0300
+++ ata-dma.c 2007-11-02 01:05:53.000000000 +0300
@@ -113,7 +113,7 @@
if
(bus_dma_tag_create(ch->dma->dmatag,ch->dma->alignment,ch->dma->boundary,
ch->dma->max_address, BUS_SPACE_MAXADDR,
NULL, NULL, ch->dma->max_iosize,
- ATA_DMA_ENTRIES, ch->dma->segsize,
+ ATA_DMA_ENTRIES - 1, ch->dma->segsize,
0, NULL, NULL, &ch->dma->data_tag))
goto error;
_______________________________________________
freebsd-hackers@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
