Alexander Sabourenkov wrote:
quoted text > 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 o=
f
quoted text > patching ata-dma.c.
> =20
Good catch!
However from my quick glimpse at the Promise sources the limit seems to=20
be 32 Dwords ie 32*4 =3D 128bytes.
I'll investigate further and ask Promise for the gory details, stay tuned=
=2E..
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=20
(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...
-S=F8ren
quoted text >
> Patches, patched and original files are at
http://lxnt.info/tx4/freebsd=
/.
quoted text >
>
> --- 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 =3D device_get_softc(dev);
> +=09
> /* note start and stop are not used here */
> ata_dmainit(dev);
> +
> + if (ch->dma)
> + ch->dma->setprd =3D 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 =3D xsc;
> + struct ata_dma_prdentry *prd =3D args->dmatab;
> + int i;
> +
> + if ((args->error =3D error))
> + return;
> +
> + for (i =3D 0; i < nsegs; i++) {
> + prd[i].addr =3D htole32(segs[i].ds_addr);
> + prd[i].count =3D 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 =3D htole32(segs[i - 1].ds_len - PDC_MAXLASTSGSIZE);=
quoted text > + prd[i].count =3D htole32(PDC_MAXLASTSGSIZE);
> + prd[i].addr =3D htole32(segs[i - 1].ds_addr + PDC_MAXLASTSGSIZE);
> + i ++;
> + nsegs ++;
> + }
> +
> + prd[i - 1].count |=3D htole32(ATA_DMA_EOT);
> + args->nsegs =3D 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->boundar=
y,
quoted text > 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;
>
>
> =20
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