Patchwork [U-Boot,V2] mvsata_ide: add delay after EDMA port reset

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Submitter Albert ARIBAUD
Date Oct. 31, 2011, 12:38 a.m.
Message ID <1320021522-20525-1-git-send-email-albert.u.boot@aribaud.net>
Download mbox | patch
Permalink /patch/122695/
State Rejected
Delegated to: Albert ARIBAUD
Headers show

Comments

Albert ARIBAUD - Oct. 31, 2011, 12:38 a.m.
Although fast SoCs like kirkwood can cope without it,
this delay is required by orion5x-based chips, either
because they are slower, or because they run U-Boot
from NOR, or both.

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
---
Patch history:

V2:	increase delay to 10 us for reliable ide reset from NOR FLASH
V1:	initial submission

Commit 70c55f5ab324d43093f1c8745462d92042b7306d had introduced resetting
the EDMA port on IDE reset. This obviously worked for kirkwoods, but not
for orion5x Ed Mini V2, where it made ide_reset() fail. Adding a slight
delay after returning port from reset to normal mode made ide_reset()
work again correctly.

Please check and confirm it does not break kirkwoods!

 drivers/block/mvsata_ide.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
Albert ARIBAUD - Oct. 31, 2011, 1:34 a.m.
Le 31/10/2011 01:38, Albert ARIBAUD a écrit :
> Although fast SoCs like kirkwood can cope without it,
> this delay is required by orion5x-based chips, either
> because they are slower, or because they run U-Boot
> from NOR, or both.
>
> Signed-off-by: Albert ARIBAUD<albert.u.boot@aribaud.net>

Please disregard my fit of 'post hoc ergo propter hoc' -- actually, IDE 
works just fine on Orion without this "fix" of mine; the issues I have 
with IDE sometimes not responding are due to some meddling from a CPLD 
on the ED Mini V2, not to any timing associated with this patch.

I've marked V1 and V2 as Rejected in patchwork.

Amicalement,

Patch

diff --git a/drivers/block/mvsata_ide.c b/drivers/block/mvsata_ide.c
index 1be395f..cd602f1 100644
--- a/drivers/block/mvsata_ide.c
+++ b/drivers/block/mvsata_ide.c
@@ -122,6 +122,7 @@  static int mvsata_ide_initialize_port(struct mvsata_port_registers *port)
 	writel(MVSATA_EDMA_CMD_ATA_RST, &port->edma_cmd);
 	udelay(25); /* taken from original marvell port */
 	writel(0, &port->edma_cmd);
+	udelay(10); /* wait after reset was acked -- required for orion5x */
 
 	/* Set control IPM to 3 (no low power) and DET to 1 (initialize) */
 	control = readl(&port->scontrol);