RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-12-22 Thread Vishwanath Sripathy
Paul,

Do you intend to merge this patch for 2.6.38? I did not see this in your
pull request.

Vishwa

 -Original Message-
 From: Paul Walmsley [mailto:p...@pwsan.com]
 Sent: Tuesday, October 05, 2010 8:48 PM
 To: Sripathy, Vishwanath
 Cc: linux-omap@vger.kernel.org; Premi, Sanjeev
 Subject: Re: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520
 for Global SW reset

 On Tue, 5 Oct 2010, Vishwanath BS wrote:

  This patch adds comments on precatution to be taken if Global Warm
 reset is
  used as the means to trigger sysem reset.
 
  Signed-off-by: Vishwanath BS vishwanath...@ti.com
  Cc: Paul Walmsley p...@pwsan.com

 Thanks, queued for 2.6.38 with Sanjeev's spelling fix.


 - Paul
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RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-12-22 Thread Vishwanath Sripathy
Paul,

Do you intend to merge this patch for 2.6.38? I did not see this in your
pull request.

Vishwa

 -Original Message-
 From: Paul Walmsley [mailto:p...@pwsan.com]
 Sent: Tuesday, October 05, 2010 8:48 PM
 To: Sripathy, Vishwanath
 Cc: linux-omap@vger.kernel.org; Premi, Sanjeev
 Subject: Re: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520
 for Global SW reset

 On Tue, 5 Oct 2010, Vishwanath BS wrote:

  This patch adds comments on precatution to be taken if Global Warm
 reset is
  used as the means to trigger sysem reset.
 
  Signed-off-by: Vishwanath BS vishwanath...@ti.com
  Cc: Paul Walmsley p...@pwsan.com

 Thanks, queued for 2.6.38 with Sanjeev's spelling fix.


 - Paul
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RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-12-22 Thread Sripathy, Vishwanath
Paul,

 -Original Message-
 From: Paul Walmsley [mailto:p...@pwsan.com]
 Sent: Tuesday, October 05, 2010 8:48 PM
 To: Sripathy, Vishwanath
 Cc: linux-omap@vger.kernel.org; Premi, Sanjeev
 Subject: Re: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520
 for Global SW reset

 On Tue, 5 Oct 2010, Vishwanath BS wrote:

  This patch adds comments on precatution to be taken if Global Warm
 reset is
  used as the means to trigger sysem reset.
 
  Signed-off-by: Vishwanath BS vishwanath...@ti.com
  Cc: Paul Walmsley p...@pwsan.com

 Thanks, queued for 2.6.38 with Sanjeev's spelling fix.

Do you intend to merge this patch for 2.6.38? I did not see this in
your pull request.

Vishwa



 - Paul
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RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-12-22 Thread Vishwanath Sripathy
Paul,
Pls ignore my other 2 emails. There were some issues in my mailbox.

Vishwa

 -Original Message-
 From: Sripathy, Vishwanath [mailto:vishwanath...@ti.com]
 Sent: Wednesday, December 22, 2010 1:58 PM
 To: Paul Walmsley
 Cc: linux-omap@vger.kernel.org; Premi, Sanjeev
 Subject: RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520
 for Global SW reset

 Paul,

  -Original Message-
  From: Paul Walmsley [mailto:p...@pwsan.com]
  Sent: Tuesday, October 05, 2010 8:48 PM
  To: Sripathy, Vishwanath
  Cc: linux-omap@vger.kernel.org; Premi, Sanjeev
  Subject: Re: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520
  for Global SW reset
 
  On Tue, 5 Oct 2010, Vishwanath BS wrote:
 
   This patch adds comments on precatution to be taken if Global
 Warm
  reset is
   used as the means to trigger sysem reset.
  
   Signed-off-by: Vishwanath BS vishwanath...@ti.com
   Cc: Paul Walmsley p...@pwsan.com
 
  Thanks, queued for 2.6.38 with Sanjeev's spelling fix.

 Do you intend to merge this patch for 2.6.38? I did not see this in
 your pull request.

 Vishwa

 
 
  - Paul
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RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-12-22 Thread Paul Walmsley
Hi Vishwa

On Wed, 22 Dec 2010, Vishwanath Sripathy wrote:

 Do you intend to merge this patch for 2.6.38? I did not see this in your
 pull request.

You are right, I'm missing this one and Rajendra's 16-bit hwmod register 
patch, both of which should be in there.  I will update the branch and 
send another pull request.

- Paul
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RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-12-22 Thread Paul Walmsley
On Wed, 22 Dec 2010, Paul Walmsley wrote:

 On Wed, 22 Dec 2010, Vishwanath Sripathy wrote:
 
  Do you intend to merge this patch for 2.6.38? I did not see this in your
  pull request.
 
 You are right, I'm missing this one and Rajendra's 16-bit hwmod register 
 patch, both of which should be in there.  I will update the branch and 
 send another pull request.

(Actually Rajendra's patch went in at 2.6.37 so we are okay with that 
one)


- Paul
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RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-12-22 Thread Paul Walmsley
On Wed, 22 Dec 2010, Paul Walmsley wrote:

 On Wed, 22 Dec 2010, Vishwanath Sripathy wrote:
 
  Do you intend to merge this patch for 2.6.38? I did not see this in your
  pull request.

Here's the updated patch.


- Paul


From: Vishwanath BS vishwanath...@ti.com
Date: Tue, 5 Oct 2010 19:35:34 +0530
Subject: [PATCH] OMAP3: SDRC: Add comments on Errata i520 for Global SW reset

This patch adds comments on precaution to be taken if Global Warm reset is
used as the means to trigger system reset.

Signed-off-by: Vishwanath BS vishwanath...@ti.com
[p...@pwsan.com: fixed typos, one mentioned by Sanjeev]
Signed-off-by: Paul Walmsley p...@pwsan.com
Cc: Sanjeev Premi pr...@ti.com
---
 arch/arm/mach-omap2/prcm.c |   28 
 1 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-omap2/prcm.c b/arch/arm/mach-omap2/prcm.c
index c22e726..679bcd2 100644
--- a/arch/arm/mach-omap2/prcm.c
+++ b/arch/arm/mach-omap2/prcm.c
@@ -74,6 +74,34 @@ void omap_prcm_arch_reset(char mode, const char *cmd)
WARN_ON(1);
}
 
+   /*
+* As per Errata i520, in some cases, user will not be able to
+* access DDR memory after warm-reset.
+* This situation occurs while the warm-reset happens during a read
+* access to DDR memory. In that particular condition, DDR memory
+* does not respond to a corrupted read command due to the warm
+* reset occurrence but SDRC is waiting for read completion.
+* SDRC is not sensitive to the warm reset, but the interconnect is
+* reset on the fly, thus causing a misalignment between SDRC logic,
+* interconnect logic and DDR memory state.
+* WORKAROUND:
+* Steps to perform before a Warm reset is trigged:
+* 1. enable self-refresh on idle request
+* 2. put SDRC in idle
+* 3. wait until SDRC goes to idle
+* 4. generate SW reset (Global SW reset)
+*
+* Steps to be performed after warm reset occurs (in bootloader):
+* if HW warm reset is the source, apply below steps before any
+* accesses to SDRAM:
+* 1. Reset SMS and SDRC and wait till reset is complete
+* 2. Re-initialize SMS, SDRC and memory
+*
+* NOTE: Above work around is required only if arch reset is implemented
+* using Global SW reset(GLOBAL_SW_RST). DPLL3 reset does not need
+* the WA since it resets SDRC as well as part of cold reset.
+*/
+
/* XXX should be moved to some OMAP2/3 specific code */
omap2_prm_set_mod_reg_bits(OMAP_RST_DPLL3_MASK, prcm_offs,
   OMAP2_RM_RSTCTRL);
-- 
1.7.2.3

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RE: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-10-05 Thread Premi, Sanjeev
 -Original Message-
 From: linux-omap-ow...@vger.kernel.org 
 [mailto:linux-omap-ow...@vger.kernel.org] On Behalf Of 
 Sripathy, Vishwanath
 Sent: Tuesday, October 05, 2010 7:36 PM
 To: linux-omap@vger.kernel.org
 Cc: Sripathy, Vishwanath; Paul Walmsley
 Subject: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 
 for Global SW reset
 
 This patch adds comments on precatution to be taken if Global 

s/precatution /precaution/ ?

[snip]..[snip]

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Re: [PATCHv3] OMAP3: SDRC : Add comments on Errata i520 for Global SW reset

2010-10-05 Thread Paul Walmsley
On Tue, 5 Oct 2010, Vishwanath BS wrote:

 This patch adds comments on precatution to be taken if Global Warm reset is
 used as the means to trigger sysem reset.
 
 Signed-off-by: Vishwanath BS vishwanath...@ti.com
 Cc: Paul Walmsley p...@pwsan.com

Thanks, queued for 2.6.38 with Sanjeev's spelling fix.


- Paul
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