[PATCH] tmio_mmc: Revise a limit of the data size

[PATCH] tmio_mmc: Revise a limit of the data size

[Yusuke Goda]

Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
---
 drivers/mmc/host/tmio_mmc.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c
index ee7d0a5..cac1c97 100644
--- a/drivers/mmc/host/tmio_mmc.c
+++ b/drivers/mmc/host/tmio_mmc.c
@@ -661,7 +661,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
 		 data->blksz, data->blocks);

 	/* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
-	if (data->blksz < 4 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
+	if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
 		pr_err("%s: %d byte block unsupported in 4 bit mode\n",
 		       mmc_hostname(host->mmc), data->blksz);
 		return -EINVAL;
-- 
1.7.0

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Andrew Morton]

On Wed, 07 Jul 2010 11:01:20 +0900
Yusuke Goda <yusuke.goda.sx@renesas.com> wrote:

> Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
> ---
>  drivers/mmc/host/tmio_mmc.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c
> index ee7d0a5..cac1c97 100644
> --- a/drivers/mmc/host/tmio_mmc.c
> +++ b/drivers/mmc/host/tmio_mmc.c
> @@ -661,7 +661,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
>  		 data->blksz, data->blocks);
> 
>  	/* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
> -	if (data->blksz < 4 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
> +	if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
>  		pr_err("%s: %d byte block unsupported in 4 bit mode\n",
>  		       mmc_hostname(host->mmc), data->blksz);
>  		return -EINVAL;

Again, please provide a suitable description for this change.

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Yusuke Goda]

Hi Andrew

Andrew Morton wrote:
> On Wed, 07 Jul 2010 11:01:20 +0900
> Yusuke Goda <yusuke.goda.sx@renesas.com> wrote:
> 
>> Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
>> ---
>>  drivers/mmc/host/tmio_mmc.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c
>> index ee7d0a5..cac1c97 100644
>> --- a/drivers/mmc/host/tmio_mmc.c
>> +++ b/drivers/mmc/host/tmio_mmc.c
>> @@ -661,7 +661,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
>>  		 data->blksz, data->blocks);
>>
>>  	/* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
>> -	if (data->blksz < 4 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
>> +	if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
>>  		pr_err("%s: %d byte block unsupported in 4 bit mode\n",
>>  		       mmc_hostname(host->mmc), data->blksz);
>>  		return -EINVAL;
> 
> Again, please provide a suitable description for this change.
I think the data size is not limited by MMC_BUS_WIDTH_x.
I confirmed that data transmission of 2Byte was performed without a problem.

Thanks,
Goda

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Matt Fleming]

On Tue, 13 Jul 2010 11:32:33 +0900
Yusuke Goda <yusuke.goda.sx@renesas.com> wrote:

> Hi Andrew
> 
> Andrew Morton wrote:
> > On Wed, 07 Jul 2010 11:01:20 +0900
> > Yusuke Goda <yusuke.goda.sx@renesas.com> wrote:
> > 
> >> Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
> >> ---
> >>  drivers/mmc/host/tmio_mmc.c |    2 +-
> >>  1 files changed, 1 insertions(+), 1 deletions(-)
> >>
> >> diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c
> >> index ee7d0a5..cac1c97 100644
> >> --- a/drivers/mmc/host/tmio_mmc.c
> >> +++ b/drivers/mmc/host/tmio_mmc.c
> >> @@ -661,7 +661,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
> >>  		 data->blksz, data->blocks);
> >>
> >>  	/* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
> >> -	if (data->blksz < 4 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
> >> +	if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
> >>  		pr_err("%s: %d byte block unsupported in 4 bit mode\n",
> >>  		       mmc_hostname(host->mmc), data->blksz);
> >>  		return -EINVAL;
> > 
> > Again, please provide a suitable description for this change.
> I think the data size is not limited by MMC_BUS_WIDTH_x.
> I confirmed that data transmission of 2Byte was performed without a problem.

This patch hasn't been picked up. I'm assuming that's because Andrew is
still unhappy with the changelog.

Andrew, how about something like,

"When running in 4-bit bus width mode, it is entirely possible to
transfer data in block sizes of 2 bytes and larger. Relax the
conditional check to allow 2-byte data block transfers which were
previously disallowed."

Yusuke, have I interpreted your changelog correctly? Also note that
your patch should remove the comment above the conditional that says,
"Hardware cannot perform 1 and 2 byte requests in 4 bit mode".

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Andrew Morton]

On Wed, 25 Aug 2010 22:52:08 +0100
Matt Fleming <matt@console-pimps.org> wrote:

> On Tue, 13 Jul 2010 11:32:33 +0900
> Yusuke Goda <yusuke.goda.sx@renesas.com> wrote:
> 
> > Hi Andrew
> > 
> > Andrew Morton wrote:
> > > On Wed, 07 Jul 2010 11:01:20 +0900
> > > Yusuke Goda <yusuke.goda.sx@renesas.com> wrote:
> > > 
> > >> Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
> > >> ---
> > >>  drivers/mmc/host/tmio_mmc.c |    2 +-
> > >>  1 files changed, 1 insertions(+), 1 deletions(-)
> > >>
> > >> diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c
> > >> index ee7d0a5..cac1c97 100644
> > >> --- a/drivers/mmc/host/tmio_mmc.c
> > >> +++ b/drivers/mmc/host/tmio_mmc.c
> > >> @@ -661,7 +661,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
> > >>  		 data->blksz, data->blocks);
> > >>
> > >>  	/* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
> > >> -	if (data->blksz < 4 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
> > >> +	if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
> > >>  		pr_err("%s: %d byte block unsupported in 4 bit mode\n",
> > >>  		       mmc_hostname(host->mmc), data->blksz);
> > >>  		return -EINVAL;
> > > 
> > > Again, please provide a suitable description for this change.
> > I think the data size is not limited by MMC_BUS_WIDTH_x.
> > I confirmed that data transmission of 2Byte was performed without a problem.
> 
> This patch hasn't been picked up. I'm assuming that's because Andrew is
> still unhappy with the changelog.

Actually I don't know what happened with this.  I merged it on July 8
and appear to have dropped it on July 27, but I can't find its
removed-from-mm email so I don't know why I dropped it.  Weird.

Oh well, I merged it again.  Is 2.6.37 an appropriate merge schedule?

Also, I tend not to handle tmio_mmc patches - usually Paul patches that
driver.

> Andrew, how about something like,
> 
> "When running in 4-bit bus width mode, it is entirely possible to
> transfer data in block sizes of 2 bytes and larger. Relax the
> conditional check to allow 2-byte data block transfers which were
> previously disallowed."

thanks.

> Yusuke, have I interpreted your changelog correctly? Also note that
> your patch should remove the comment above the conditional that says,
> "Hardware cannot perform 1 and 2 byte requests in 4 bit mode".

this?

--- a/drivers/mmc/host/tmio_mmc.c~tmio_mmc-revise-a-limit-of-the-data-size-fix
+++ a/drivers/mmc/host/tmio_mmc.c
@@ -660,7 +660,6 @@ static int tmio_mmc_start_data(struct tm
 	pr_debug("setup data transfer: blocksize %08x  nr_blocks %d\n",
 		 data->blksz, data->blocks);
 
-	/* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
 	if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
 		pr_err("%s: %d byte block unsupported in 4 bit mode\n",
 		       mmc_hostname(host->mmc), data->blksz);
_

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Matt Fleming]

On Wed, 25 Aug 2010 15:05:02 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:

> Actually I don't know what happened with this.  I merged it on July 8
> and appear to have dropped it on July 27, but I can't find its
> removed-from-mm email so I don't know why I dropped it.  Weird.

Oh, interesting.

> Oh well, I merged it again.  Is 2.6.37 an appropriate merge schedule?

I'll defer that to Goda and Paul but that seems reasonable to me.

> > Yusuke, have I interpreted your changelog correctly? Also note that
> > your patch should remove the comment above the conditional that says,
> > "Hardware cannot perform 1 and 2 byte requests in 4 bit mode".
> 
> this?
> 
> --- a/drivers/mmc/host/tmio_mmc.c~tmio_mmc-revise-a-limit-of-the-data-size-fix
> +++ a/drivers/mmc/host/tmio_mmc.c
> @@ -660,7 +660,6 @@ static int tmio_mmc_start_data(struct tm
>  	pr_debug("setup data transfer: blocksize %08x  nr_blocks %d\n",
>  		 data->blksz, data->blocks);
>  
> -	/* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
>  	if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
>  		pr_err("%s: %d byte block unsupported in 4 bit mode\n",
>  		       mmc_hostname(host->mmc), data->blksz);
> _
> 

I was thinking more like changing the comment to say "Hardware cannot
perform 1 byte requests in 4 bit mode" but that's evident from the
check. So sure, removing it seems sane.

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Ian Molton]

Probably dropped because I complained about two things,

1) The patch doesnt check what the hardware is underneath before
arbitrarily changing the parameters relied on by some hardware

2) Removing a comment I put there for a good reason without explaining why.

"It works on my hardware" is not a good enough excuse.

-- 
Ian Molton
Linux, Automotive, and other hacking:
http://www.mnementh.co.uk/



On 25 August 2010 23:05, Andrew Morton <akpm@linux-foundation.org> wrote:
> On Wed, 25 Aug 2010 22:52:08 +0100
> Matt Fleming <matt@console-pimps.org> wrote:
>
>> On Tue, 13 Jul 2010 11:32:33 +0900
>> Yusuke Goda <yusuke.goda.sx@renesas.com> wrote:
>>
>> > Hi Andrew
>> >
>> > Andrew Morton wrote:
>> > > On Wed, 07 Jul 2010 11:01:20 +0900
>> > > Yusuke Goda <yusuke.goda.sx@renesas.com> wrote:
>> > >
>> > >> Signed-off-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
>> > >> ---
>> > >>  drivers/mmc/host/tmio_mmc.c |    2 +-
>> > >>  1 files changed, 1 insertions(+), 1 deletions(-)
>> > >>
>> > >> diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c
>> > >> index ee7d0a5..cac1c97 100644
>> > >> --- a/drivers/mmc/host/tmio_mmc.c
>> > >> +++ b/drivers/mmc/host/tmio_mmc.c
>> > >> @@ -661,7 +661,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
>> > >>                   data->blksz, data->blocks);
>> > >>
>> > >>          /* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
>> > >> -        if (data->blksz < 4 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
>> > >> +        if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
>> > >>                  pr_err("%s: %d byte block unsupported in 4 bit mode\n",
>> > >>                         mmc_hostname(host->mmc), data->blksz);
>> > >>                  return -EINVAL;
>> > >
>> > > Again, please provide a suitable description for this change.
>> > I think the data size is not limited by MMC_BUS_WIDTH_x.
>> > I confirmed that data transmission of 2Byte was performed without a problem.
>>
>> This patch hasn't been picked up. I'm assuming that's because Andrew is
>> still unhappy with the changelog.
>
> Actually I don't know what happened with this.  I merged it on July 8
> and appear to have dropped it on July 27, but I can't find its
> removed-from-mm email so I don't know why I dropped it.  Weird.
>
> Oh well, I merged it again.  Is 2.6.37 an appropriate merge schedule?
>
> Also, I tend not to handle tmio_mmc patches - usually Paul patches that
> driver.
>
>> Andrew, how about something like,
>>
>> "When running in 4-bit bus width mode, it is entirely possible to
>> transfer data in block sizes of 2 bytes and larger. Relax the
>> conditional check to allow 2-byte data block transfers which were
>> previously disallowed."
>
> thanks.
>
>> Yusuke, have I interpreted your changelog correctly? Also note that
>> your patch should remove the comment above the conditional that says,
>> "Hardware cannot perform 1 and 2 byte requests in 4 bit mode".
>
> this?
>
> --- a/drivers/mmc/host/tmio_mmc.c~tmio_mmc-revise-a-limit-of-the-data-size-fix
> +++ a/drivers/mmc/host/tmio_mmc.c
> @@ -660,7 +660,6 @@ static int tmio_mmc_start_data(struct tm
>        pr_debug("setup data transfer: blocksize %08x  nr_blocks %d\n",
>                 data->blksz, data->blocks);
>
> -       /* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */
>        if (data->blksz < 2 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) {
>                pr_err("%s: %d byte block unsupported in 4 bit mode\n",
>                       mmc_hostname(host->mmc), data->blksz);
> _
>
>

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Matt Fleming]

On Thu, Aug 26, 2010 at 02:50:09AM +0100, Ian Molton wrote:
> Probably dropped because I complained about two things,
> 
> 1) The patch doesnt check what the hardware is underneath before
> arbitrarily changing the parameters relied on by some hardware

Has anyone thought about adding a caps or flags field to the
tmio_mmc_host structure so that platform code set a bit if it can't do
2-byte data block transfers?

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Magnus Damm]

On Thu, Aug 26, 2010 at 4:24 PM, Matt Fleming <matt@console-pimps.org> wrote:
> On Thu, Aug 26, 2010 at 02:50:09AM +0100, Ian Molton wrote:
>> Probably dropped because I complained about two things,
>>
>> 1) The patch doesnt check what the hardware is underneath before
>> arbitrarily changing the parameters relied on by some hardware
>
> Has anyone thought about adding a caps or flags field to the
> tmio_mmc_host structure so that platform code set a bit if it can't do
> 2-byte data block transfers?

Good idea! There is already a good place available:

>From include/linux/mfd/tmio.h:
...
/* tmio MMC platform flags */
#define TMIO_MMC_WRPROTECT_DISABLE      (1 << 0)

Cheers,

/ magnus

Re: [PATCH] tmio_mmc: Revise a limit of the data size

[Ian Molton]

@Matt: yes, thats what I was suggesting before.

@Magnus: that looks fine.

-- 
Ian Molton
Linux, Automotive, and other hacking:
http://www.mnementh.co.uk/



On 26 August 2010 08:26, Magnus Damm <magnus.damm@gmail.com> wrote:
> On Thu, Aug 26, 2010 at 4:24 PM, Matt Fleming <matt@console-pimps.org> wrote:
>> On Thu, Aug 26, 2010 at 02:50:09AM +0100, Ian Molton wrote:
>>> Probably dropped because I complained about two things,
>>>
>>> 1) The patch doesnt check what the hardware is underneath before
>>> arbitrarily changing the parameters relied on by some hardware
>>
>> Has anyone thought about adding a caps or flags field to the
>> tmio_mmc_host structure so that platform code set a bit if it can't do
>> 2-byte data block transfers?
>
> Good idea! There is already a good place available:
>
> From include/linux/mfd/tmio.h:
> ...
> /* tmio MMC platform flags */
> #define TMIO_MMC_WRPROTECT_DISABLE      (1 << 0)
>
> Cheers,
>
> / magnus
>