Thread (18 messages) 18 messages, 6 authors, 2011-02-22
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[PATCH 5/5] mmc: sdhci: add quirk SDHCI_QUIRK_FIX_NO_INT_IN_MULTI_BLK_IO

From: Zhu Richard-R65037 <hidden>
Date: 2011-02-22 05:56:21
Also in: linux-mmc

Hi WolfSang:
I mis-understand your meaning of the IO-Accessors.
It maybe work when the IO-Accessors are used.
Wait a minute, I would resend the patches use he IO-Accessors methods.

Best Regards
Richard Zhu

-----Original Message-----
From: Zhu Richard-R65037
Sent: Tuesday, February 22, 2011 10:22 AM
To: 'Wolfram Sang'; Russell King - ARM Linux
Cc: Zhao Richard-B20223; cjb at laptop.org; eric at eukrea.com; linux-
mmc at vger.kernel.org; kernel at pengutronix.de; avorontsov at ru.mvista.com;
linux-arm-kernel at lists.infradead.org; linuxzsc at gmail.com
Subject: RE: [PATCH 5/5] mmc: sdhci: add quirk
SDHCI_QUIRK_FIX_NO_INT_IN_MULTI_BLK_IO

Hi Wolfsang:
Maybe I don't describe my thoughts clearly and exactly.
I feel it's not easy to add the the IO-accessors in every cmd execution
procedure, to make a double check why a IO-accessor is needed or not.

Best Regards
Richard Zhu

quoted
-----Original Message-----
From: Wolfram Sang [mailto:w.sang at pengutronix.de]
Sent: Monday, February 21, 2011 7:16 PM
To: Russell King - ARM Linux
Cc: Zhu Richard-R65037; Zhao Richard-B20223; cjb at laptop.org;
eric at eukrea.com; linux-mmc at vger.kernel.org; kernel at pengutronix.de;
avorontsov at ru.mvista.com; linux-arm-kernel at lists.infradead.org;
linuxzsc at gmail.com
Subject: Re: [PATCH 5/5] mmc: sdhci: add quirk
SDHCI_QUIRK_FIX_NO_INT_IN_MULTI_BLK_IO

On Mon, Feb 21, 2011 at 11:09:05AM +0000, Russell King - ARM Linux
wrote:
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On Mon, Feb 21, 2011 at 11:46:08AM +0100, Wolfram Sang wrote:
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-   if (cpu_is_mx35() || cpu_is_mx51())
+   if (cpu_is_mx53())
+           host->quirks |=
+ SDHCI_QUIRK_FIX_NO_INT_IN_MULTI_BLK_IO;
Have you tried it doing it via IO-accessors?
Richard Zhu: This quirk is used to fix a mechanism problem in
the
MMC CMDs execution procedure.
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It would be very abrupt and ugly, if the IO-accessors are added
into these original procedures.
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Please don't get it personal, but IMHO it is pretty ugly the way
it is now. This quirk is very imx-specific and calling something
like SDHCI_VENDOR_SPEC in sdhci.c looks clearly wrong to me. By
the way, what does this bit do, the description doesn't say so?
SDHCI_QUIRK_FIX_NO_INT_IN_MULTI_BLK_IO is rather too verbose.  Isn't
there a shorter version which could be used?
SDHCI_QUIRK_SDIO_MULTIBLK_INT maybe?
As I understand, the non-SDIO part is handled here:
Yes, it is. The following codes are used to solve non-sdio part.
That bit is introduced by imx53 latest spec.
I think so too that the SDHCI_VENDOR_SPEC shouldn't be used in sdhci.c
file, but I don't have better idea to fix the issue in this situation.
Option:
Make a double check when issue every MMC CMD, to figure out whether a IO-
accessor is needed or not?
Two checkpoints would be needed, one is in the sdhci_send_command
function, the other should be in sdhci_data_finish func.
How do you think this method?
quoted
+       /*Set the CMD_TYPE of the CMD12, fix no INT in MULTI_BLK IO */
+       if (host->quirks & SDHCI_QUIRK_FIX_NO_INT_IN_MULTI_BLK_IO) {
+               if (cmd->opcode == 12)
+                       flags |= SDHCI_CMD_ABORTCMD;
+       }

But I'd really like to avoid the quirk bit. Maybe we'll get a better
idea once we understand what that magic bit actually does. For a
start, we might simply set SDHCI_QUIRK_NO_MULTIBLOCK for mx53 like we
do for other imx.
As I know that, this bit is used to make the machine stat of the eSDHC IC
to be a correct stat after SDIO Multi-Read.
quoted
Regards,

   Wolfram

--
Pengutronix e.K.                           | Wolfram Sang
|
Industrial Linux Solutions                 | http://www.pengutronix.de/
|
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