lkml.org 
[lkml]   [2007]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 14/15] ide: rework the code for selecting the best DMA transfer mode
Hello, I wrote:

>>> [PATCH] ide: rework the code for selecting the best DMA transfer mode

>>> Depends on the "ide: fix UDMA/MWDMA/SWDMA masks" patch.

>> I'm now trying to rewrite hpt366.c to benefit more from these
>> patches...
>> and alas, this very patch seems to be breaking filtering (at least) in
>> this driver. :-]

Ignore me, I've seemingly misundertood the code. :-<

>>> Index: b/drivers/ide/pci/hpt366.c
>>> ===================================================================
>>> --- a/drivers/ide/pci/hpt366.c
>>> +++ b/drivers/ide/pci/hpt366.c
>>> @@ -513,43 +513,31 @@ static int check_in_drive_list(ide_drive
>>> return 0;
>>> }
>>>
>>> -static u8 hpt3xx_ratemask(ide_drive_t *drive)
>>> -{
>>> - struct hpt_info *info = pci_get_drvdata(HWIF(drive)->pci_dev);
>>> - u8 mode = info->max_mode;
>>> -
>>> - if (!eighty_ninty_three(drive) && mode)
>>> - mode = min(mode, (u8)1);
>>> - return mode;
>>> -}
>>> -
>>> /*
>>> * Note for the future; the SATA hpt37x we must set
>>> * either PIO or UDMA modes 0,4,5
>>> */
>>> - -static u8 hpt3xx_ratefilter(ide_drive_t *drive, u8 speed)
>>> +
>>> +static u8 hpt3xx_udma_filter(ide_drive_t *drive)
>>> {
>>> struct hpt_info *info = pci_get_drvdata(HWIF(drive)->pci_dev);
>>> u8 chip_type = info->chip_type;
>>> - u8 mode = hpt3xx_ratemask(drive);
>>> -
>>> - if (drive->media != ide_disk)
>>> - return min(speed, (u8)XFER_PIO_4);
>>> + u8 mode = info->max_mode;
>>> + u8 mask;
>>>
>>> switch (mode) {
>>> case 0x04:
>>> - speed = min_t(u8, speed, XFER_UDMA_6);
>>> + mask = 0x7f;
>>> break;
>>> case 0x03:
>>> - speed = min_t(u8, speed, XFER_UDMA_5);
>>> + mask = 0x3f;
>>> if (chip_type >= HPT374)
>>> break;
>>> if (!check_in_drive_list(drive, bad_ata100_5))
>>> goto check_bad_ata33;
>>> /* fall thru */
>>> case 0x02:
>>> - speed = min_t(u8, speed, XFER_UDMA_4);
>>> + mask = 0x1f;
>>>
>>> /*
>>> * CHECK ME, Does this need to be changed to HPT374 ??
>>> @@ -560,13 +548,13 @@ static u8 hpt3xx_ratefilter(ide_drive_t
>>> !check_in_drive_list(drive, bad_ata66_4))
>>> goto check_bad_ata33;
>>>
>>> - speed = min_t(u8, speed, XFER_UDMA_3);
>>> + mask = 0x0f;
>>> if (HPT366_ALLOW_ATA66_3 &&
>>> !check_in_drive_list(drive, bad_ata66_3))
>>> goto check_bad_ata33;
>>> /* fall thru */
>>> case 0x01:
>>> - speed = min_t(u8, speed, XFER_UDMA_2);
>>> + mask = 0x07;
>>>
>>> check_bad_ata33:
>>> if (chip_type >= HPT370A)

>> This case 0x01 will *never* be hit for HPT370 chip with the new
>> code, therefore the filter won't get applied.

> Oh, and for HPT36x chips used with 40c cable too (unless they're
> artificaially reduced to UltraDMA/33 by the driver #define's).

It will still get applied since the code always resorts to looking up the 'bad_ata33' list for HPT36x/370.
I've got a bit muddled in my own code -- not sure if it got much clearer after I'd untangled hpt3xx_ratemask() / hpt3xx_ratefilter() puzzle. :-)

>>> @@ -576,10 +564,10 @@ static u8 hpt3xx_ratefilter(ide_drive_t
>>> /* fall thru */
>>> case 0x00:
>>> default:
>>> - speed = min_t(u8, speed, XFER_MW_DMA_2);
>>> + mask = 0x00;
>>> break;

> Well, that case 0x00 should never actually happen.

Yeah, that's true, 'case 0x00' (and even 'default') labels could have been removed.

MBR, Sergei

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-04-20 19:53    [W:0.096 / U:0.060 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site