driver/ddr/fsl: Force enabling parity for A-009803
PATCH 1/1 driver/ddr/fsl: Force enabling parity for A-009803
Default address parity is disabled for DDR4 UDIMM for considing performance, it needs to enable parity for A-009803 workaround.
--- drivers/ddr/fsl/options.c | 3 +++ 1 file changed, 3 insertions(+)
drivers/ddr/fsl/options.c +3 -0
@@ -1016,6 +1016,9 @@ unsigned int populate_memctl_options(const common_timing_params_t *common_dimm, } } +#ifdef CONFIG_SYS_FSL_ERRATUM_A009803 + popts->ap_en =1 ; +#endif /* * BSTTOPRE precharge interval *
Signature · 1 line
2.1.0.27.g96db324
PATCH 1/1 driver/ddr/fsl: Force enabling parity for A-009803
Quoted 14 lines · Shengzhou Liu
Default address parity is disabled for DDR4 UDIMM for considing performance, it needs to enable parity for A-009803 workaround.
Signed-off-by Shengzhou Liu <[email protected]>--- drivers/ddr/fsl/options.c | 3 +++ 1 file changed, 3 insertions(+)drivers/ddr/fsl/options.c +0
-0
drivers/ddr/fsl/options.c unsigned int populate_memctl_options(const common_timing_params_t *common_dimm, · line 1024
Quoted 9 lines
drivers/ddr/fsl/options.c +3
-0@@ -1016,6 +1016,9 @@ unsigned int populate_memctl_options(const common_timing_params_t *common_dimm, } } +#ifdef CONFIG_SYS_FSL_ERRATUM_A009803 + popts->ap_en =1 ; +#endif /* * BSTTOPRE precharge interval *
Shengzhou,
It looks backward. You should detect if the condition is right before applying the workaround, not by forcing the condition.
York
PATCH 1/1 driver/ddr/fsl: Force enabling parity for A-009803
Quoted 7 lines
-----Original Message-----
From: York Sun [mailto:york.sun at nxp.com]
Sent: Friday, May 20, 2016 11:29 PM
To: Shengzhou Liu <[email protected]>; u-boot at lists.denx.de
Subject: Re: [PATCH] driver/ddr/fsl: Force enabling parity for A-009803Quoted 1 line
Quoted 6 lines
Shengzhou,
It looks backward. You should detect if the condition is right before applying the workaround, not by forcing the condition.
York
If ERRATUM_A009803 is defined, ap_en should always be enabled whatever user configures parity=on in hwconfig. As ERRATUM_A009803 is enabled only in arch-fsl-layerscape/config.h for LS2 SoC, I don't think we need to check anything other. What condition do you mean?
-Shengzhou
PATCH 1/1 driver/ddr/fsl: Force enabling parity for A-009803
Quoted 9 lines · Shengzhou Liu
Quoted 9 lines
-----Original Message-----
From: York Sun [mailto:york.sun at nxp.com]
Sent: Friday, May 20, 2016 11:29 PM
To: Shengzhou Liu <[email protected]>; u-boot at lists.denx.de
Subject: Re: [PATCH] driver/ddr/fsl: Force enabling parity for A-009803Quoted 1 line
Shengzhou,
Quoted 9 lines
Quoted 4 lines
It looks backward. You should detect if the condition is right before applying the workaround, not by forcing the condition.
York
If
ERRATUM_A009803is defined,ap_enshould always be enabled whatever user configures parity=on in hwconfig. AsERRATUM_A009803is enabled only inarch-fsl-layerscape/config.hfor LS2 SoC, I don't think we need to check anything other. What condition do you mean?
Shengzhou,
My point is you should force ap=1. Do you mean if ERRATUM_A009803 is enabled, users are forced to use address parity? That doesn't sound right. We have been running UDIMM without address parity for a long time.
York
PATCH 1/1 driver/ddr/fsl: Force enabling parity for A-009803
Quoted 8 lines
-----Original Message-----
From: York Sun [mailto:york.sun at nxp.com]
Sent: Monday, May 23, 2016 11:33 PM
To: Shengzhou Liu <[email protected]>; u-boot at lists.denx.de
Subject: Re: [PATCH] driver/ddr/fsl: Force enabling parity for A-009803 Shengzhou,
Quoted 6 lines
My point is you should force ap=1. Do you mean if
ERRATUM_A009803is enabled, users are forced to use address parity? That doesn't sound right. We have been running UDIMM without address parity for a long time.York
York,
My understanding is that ERRATUM_A009803 may still happen whatever ap_en is enabled or disabled. To apply the workaround of A009803, it requires ap_en is enabled. Is your understanding that if we disable ap_en, ERRATUM_A009803 will never happen? The CE document doesn't explain clearly this. In last mail, did you mean we should force ap_en = 0 in case of A-009803?
Shengzhou
PATCH 1/1 driver/ddr/fsl: Force enabling parity for A-009803
Quoted 12 lines · Shengzhou Liu
Quoted 12 lines
-----Original Message-----
From: York Sun [mailto:york.sun at nxp.com]
Sent: Monday, May 23, 2016 11:33 PM
To: Shengzhou Liu <[email protected]>; u-boot at lists.denx.de
Subject: Re: [PATCH] driver/ddr/fsl: Force enabling parity for A-009803 Shengzhou,My point is you should force ap=1. Do you mean if
ERRATUM_A009803is enabled, users are forced to use address parity? That doesn't sound right. We have been running UDIMM without address parity for a long time.
Quoted 8 lines
Quoted 2 lines
York
York,
My understanding is thatERRATUM_A009803may still happen whateverap_enis enabled or disabled. To apply the workaround of A009803, it requiresap_enis enabled. Is your understanding that if we disableap_en,ERRATUM_A009803will never happen? The CE document doesn't explain clearly this. In last mail, did you mean we should forceap_en= 0 in case of A-009803?
Sorry I had a typo. I meant you should NOT force ap=1. Let me explain. The erratum tells you _if_ address parity is used, for either UDIMM or RDIMM, you need to implement the workaround, as step 1, 2, 3, ... We understand users don't have a choice for RDIMM, the address parity is always enabled. But for UDIMM, users can choose not to enable it. Your _this_ patch forces the address parity to be true, regardless of user's choice. I think this is wrong.
The erratum always applies to affected SoCs, but the address parity is not always enabled. That's what I meant for "condition".
York