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From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
To: Alan <alan@lxorguk.ukuu.org.uk>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>,
	linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 13/15] ide: fix UDMA/MWDMA/SWDMA masks
Date: Thu, 25 Jan 2007 18:40:23 +0300	[thread overview]
Message-ID: <45B8CF67.2070401@ru.mvista.com> (raw)
In-Reply-To: <45B620D7.3030501@ru.mvista.com>

Hello.

Sergei Shtylyov wrote:

>> Not a suprise to be honest. I fixed some of the ALi stuff when I did it
>> and I think that was pushed back into drivers/ide. The CMD64x hasn't had
>> much love really.

>    Another buglet found by random glancing at this driver:

> /**
>  *      cmd648_dma_stop -       DMA stop callback
>  *      @qc: Command in progress
>  *
>  *      DMA has completed.
>  */

> static void cmd648_bmdma_stop(struct ata_queued_cmd *qc)
> {
>         struct ata_port *ap = qc->ap;
>         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
>         u8 dma_intr;
>         int dma_reg = ap->port_no ? ARTTIM23_INTR_CH1 : CFR_INTR_CH0;
>         int dma_mask = ap->port_no ? ARTTIM2 : CFR;
> 
>         ata_bmdma_stop(qc);
> 
>         pci_read_config_byte(pdev, dma_reg, &dma_intr);
>         pci_write_config_byte(pdev, dma_reg, dma_intr | dma_mask);
> }

>    dma_reg and dma_mask initializers must have been swapped since 
> ARTTIM2 and CFR are regster names.  So, the code reads/writes 
> semi-random regs...

    BTW, on PCI0646U2 and later chips, the interrupt status (it's not really 
DMA interrupt status but a latched INTRQ signal not "coupled" with DMA logic, 
according to the datasheets) can be read from MRDMODE reg. which is accessible 
in I/O space at BMIDE base + 1 which is certainly faster.  That's what 
drivers/ide/cmd64x.c is doing in its test_dma_irq() method (however, it's 
doign this on PCI0643 and early revs of PCI0646 which don't have these bits).
The driver's dma_end() method is acting really strange: it checks if the cjip 
is PCI-648/9 and reads the PCI config space to clear those interrupt bits 
while these chips have them in I/O mapped MRDMODE; OTOH, it ignores these bits 
on earlier chips which have them in oonfig. space only (CFR/ARTTIM23 regs)... 
go figure.  I'm going to clean this up but don't heve the h/w handy... :-/

>> Wouldn't mind the older 64x (not 640) data sheets if they are sharable.

>    Sent what I had on this machine.  Will looks for newer revision of 
> PCJ0646U2 spec elsewhere...

    Sent rev. 1.3... Hopefully gkernel.sourceforge.net/specs/ will be updated.

MBR, Sergei

  reply	other threads:[~2007-01-25 15:40 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-19  0:30 [PATCH 0/15] IDE quilt tree updated Bartlomiej Zolnierkiewicz
2007-01-19  0:31 ` [PATCH 1/15] ACPI support for IDE devices Bartlomiej Zolnierkiewicz
2007-01-19  0:31 ` [PATCH 2/15] via82cxxx/pata_via: correct PCI_DEVICE_ID_VIA_SATA_EIDE ID and add support for CX700 and 8237S Bartlomiej Zolnierkiewicz
2007-01-19  0:31 ` [PATCH 3/15] it8213: fix build and ->ultra_mask Bartlomiej Zolnierkiewicz
2007-01-19  0:31 ` [PATCH 4/15] ide: convert ide_hwif_t.mmio into flag Bartlomiej Zolnierkiewicz
2007-01-19  0:31 ` [PATCH 5/15] hpt34x: hpt34x_tune_chipset() (->speedproc) fix Bartlomiej Zolnierkiewicz
2007-01-19  0:31 ` [PATCH 6/15] atiixp/jmicron/triflex: fix PIO fallback Bartlomiej Zolnierkiewicz
2007-01-19  0:31 ` [PATCH 7/15] piix: cleanup Bartlomiej Zolnierkiewicz
2007-01-19  0:31 ` [PATCH 8/15] ide: disable DMA in ->ide_dma_check for "no IORDY" case Bartlomiej Zolnierkiewicz
2007-01-19 16:26   ` Sergei Shtylyov
     [not found]     ` <58cb370e0701191047h524434eobdb9d86ed614bc71@mail.gmail.com>
2007-01-19 19:11       ` Bartlomiej Zolnierkiewicz
2007-01-19 19:35         ` Sergei Shtylyov
     [not found]           ` <58cb370e0701191200i10119313i4aacae9c504a02e4@mail.gmail.com>
2007-01-19 21:43             ` Bartlomiej Zolnierkiewicz
2007-01-20 17:09               ` Sergei Shtylyov
     [not found]                 ` <58cb370e0701200947p578f4d74g1fee511ded6c9a77@mail.gmail.com>
2007-01-20 18:21                   ` Bartlomiej Zolnierkiewicz
2007-01-20 18:41                     ` Sergei Shtylyov
2007-01-25 17:03                     ` Sergei Shtylyov
2007-01-19  0:32 ` [PATCH 9/15] sgiioc4: fix sgiioc4_ide_dma_check() to enable/disable DMA properly Bartlomiej Zolnierkiewicz
2007-01-19  0:32 ` [PATCH 10/15] ide: add ide_set_dma() helper Bartlomiej Zolnierkiewicz
2007-01-20 20:22   ` Sergei Shtylyov
2007-01-19  0:32 ` [PATCH 11/15] ide: make ide_hwif_t.ide_dma_{host_off,off_quietly} void Bartlomiej Zolnierkiewicz
2007-01-20 20:56   ` Sergei Shtylyov
     [not found]     ` <58cb370e0702021206h205ff983r88fb4bdbea42ed9f@mail.gmail.com>
2007-02-02 22:39       ` Bartlomiej Zolnierkiewicz
2007-01-19  0:32 ` [PATCH 12/15] ide: make ide_hwif_t.ide_dma_host_on void Bartlomiej Zolnierkiewicz
2007-01-20 20:46   ` Sergei Shtylyov
     [not found]     ` <58cb370e0702021128g15cac87ar507c20e78ded9464@mail.gmail.com>
2007-02-02 21:16       ` Bartlomiej Zolnierkiewicz
2007-03-26 17:19   ` Sergei Shtylyov
2007-04-20 20:36     ` Sergei Shtylyov
2007-01-19  0:32 ` [PATCH 13/15] ide: fix UDMA/MWDMA/SWDMA masks Bartlomiej Zolnierkiewicz
2007-01-22 16:19   ` Sergei Shtylyov
     [not found]     ` <58cb370e0702021606v4efa6143lf060e6aab9782c35@mail.gmail.com>
2007-02-03  0:39       ` Bartlomiej Zolnierkiewicz
2007-02-03 16:30         ` Sergei Shtylyov
2007-01-22 18:17   ` Sergei Shtylyov
2007-01-22 18:46     ` Alan
2007-01-22 20:28       ` Sergei Shtylyov
2007-01-22 21:31         ` Alan
2007-01-22 22:39           ` Jeff Garzik
2007-01-23 14:51           ` Sergei Shtylyov
2007-01-25 15:40             ` Sergei Shtylyov [this message]
2007-01-31 20:38       ` Sergei Shtylyov
2007-01-31 23:24         ` Alan
     [not found]     ` <58cb370e0702021606m4eb6f682xfa4bf769d398cf9@mail.gmail.com>
2007-02-03  0:50       ` Bartlomiej Zolnierkiewicz
2007-01-19  0:32 ` [PATCH 14/15] ide: rework the code for selecting the best DMA transfer mode Bartlomiej Zolnierkiewicz
2007-01-22 19:48   ` Sergei Shtylyov
     [not found]     ` <58cb370e0702021207o435f39cdsf3abb0d55829fc45@mail.gmail.com>
2007-02-02 23:57       ` Bartlomiej Zolnierkiewicz
2007-01-19  0:32 ` [PATCH 15/15] ide: add ide_tune_dma() helper Bartlomiej Zolnierkiewicz
2007-02-03 13:53 [PATCH 11/15] ide: make ide_hwif_t.ide_dma_{host_off,off_quietly} void Bartlomiej Zolnierkiewicz
2007-02-03 13:53 ` [PATCH 13/15] ide: fix UDMA/MWDMA/SWDMA masks Bartlomiej Zolnierkiewicz
2007-02-03 17:24 Bartlomiej Zolnierkiewicz
2007-04-22 16:19 ` Sergei Shtylyov

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