Hello.
On 10/14/2011 05:43 PM, Bartlomiej Zolnierkiewicz wrote:
From: Bartlomiej Zolnierkiewicz<bzolnier@xxxxxxxxx>
Subject: [PATCH v2] ata_piix: unify code for programming PIO and MWDMA timings
Besides making things noticably simpler it results in ~2% decrease in
the driver LOC count and also ~2% decrease in the driver binary size
(as measured on x86-32).
Fix piix_set_piomode() documentation while at it.
Signed-off-by: Bartlomiej Zolnierkiewicz<bzolnier@xxxxxxxxx>
I'm still inclined to NAK this patch.
---
v2: remove use_mwdma variable and fix comment style
earlier references:
https://lkml.org/lkml/2011/2/8/99
drivers/ata/ata_piix.c | 111 ++++++++++++++++---------------------------------
1 file changed, 38 insertions(+), 73 deletions(-)
Index: b/drivers/ata/ata_piix.c
===================================================================
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
[...]
@@ -811,31 +822,20 @@ static void do_pata_set_dmamode(struct a
[...]
- if (ap->udma_mask)
- pci_read_config_byte(dev, 0x48,&udma_enable);
Don't think you should remove this.
-
if (speed>= XFER_UDMA_0) {
- unsigned int udma = adev->dma_mode - XFER_UDMA_0;
+ unsigned int udma = speed - XFER_UDMA_0;
u16 udma_timing;
u16 ideconf;
int u_clock, u_speed;
+ spin_lock_irqsave(&piix_lock, flags);
+
+ pci_read_config_byte(dev, 0x48,&udma_enable);
But you should also clear the UDMA enable bit when setting an MWDMA mode, no?
+
/*
* UDMA is handled by a combination of clock switching and
* selection of dividers
@@ -868,56 +868,21 @@ static void do_pata_set_dmamode(struct a
performance (WR_PingPong_En) */
pci_write_config_word(dev, 0x54, ideconf);
}
+
+ pci_write_config_byte(dev, 0x48, udma_enable);
+
+ spin_unlock_irqrestore(&piix_lock, flags);
} else {
- /*
- * MWDMA is driven by the PIO timings. We must also enable
- * IORDY unconditionally along with TIME1. PPE has already
- * been set when the PIO timing was set.
- */
- unsigned int mwdma = adev->dma_mode - XFER_MW_DMA_0;
- unsigned int control;
- u8 slave_data;
+ /* MWDMA is driven by the PIO timings. */
+ unsigned int mwdma = speed - XFER_MW_DMA_0;
const unsigned int needed_pio[3] = {
XFER_PIO_0, XFER_PIO_3, XFER_PIO_4
};
int pio = needed_pio[mwdma] - XFER_PIO_0;
[...]
- if (ap->udma_mask)
- udma_enable&= ~(1<< devid);
Still don't understand why you're removing this code.
-
- pci_write_config_word(dev, master_port, master_data);
+ /* XFER_PIO_0 is never used currently */
+ piix_set_timings(ap, adev, pio);
}
- /* Don't scribble on 0x48 if the controller does not support UDMA */
- if (ap->udma_mask)
- pci_write_config_byte(dev, 0x48, udma_enable);
Should have kept this one too...
We still have following code at the end of piix_set_timings():
/* Ensure the UDMA bit is off - it will be turned back on if
UDMA is selected */
if (ap->udma_mask) {
pci_read_config_byte(dev, 0x48,&udma_enable);
udma_enable&= ~(1<< (2 * ap->port_no + adev->devno));
pci_write_config_byte(dev, 0x48, udma_enable);
}
so everything should be OK.
Ah, I should have looked... Didn't expect it to be there, and it in fact
shouldn't be there, but now I'm OK with your patch. :-)
WBR, Sergei
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