On Fri, Dec 03, 2010 at 05:21:10AM +0800, Hein_Tibosch wrote:
> Hi Sahitya,
> On 2-12-2010 19:16, Sahitya Tummala wrote:
> > Hi Hein Tibosch,
> >
> > On Fri, 2010-09-03 at 05:34 +0800, Hein_Tibosch wrote:
> >> In the latest releases of the mmc driver, the freq during initialization
> >> is set to a fixed 400 Khz. This was reportedly too fast for several
> >> users. As there doesn't seem to be an ideal frequency which-works-for-all,
> >> Pierre suggested to let the driver try several frequencies.
> >> <cut>
> >> + /*
> >> + * First we search for SDIO...
> >> + */
> >> + err = mmc_send_io_op_cond(host, 0, &ocr);
> >> + if (!err) {
> >> + if (mmc_attach_sdio(host, ocr)) {
> >> + mmc_claim_host(host);
> >> + /* try SDMEM (but not MMC) even if SDIO is broken */
> >> + if (mmc_send_app_op_cond(host, 0, &ocr))
> > In case of SDIO error, mmc_power_off() is getting called as part of
> > mmc_detach_bus(). Shouldn't we power up the host before checking for
> > SDMEM? Any comments?
> I think you should ask Michal Miroslaw, as he wrote the patch for the
> SD-combo (IO + mem)*
>
> But yes, in case of a failure, mmc_attach_sdio() will call mmc_detach_bus()
> which in turn will call mmc_power_off()
>
> And so it should be mmc_power_up() again before trying to detect SD memory.
Yes, you are right! This explains some things...
Please try attached patch. (Not tested, but obvious enough.)
Best Regards,
Michał Mirosław
---
mmc: fix detection of memory part of SD-combo card with broken SDIO
In case of failure, mmc_attach_sdio() will power off the SD bus.
Power it up and reinitialize before trying SD memory detection.
Reported-by: Sahitya Tummala <stummala@xxxxxxxxxxxxxx>
Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
---
drivers/mmc/core/core.c | 5 +++++
1 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 6286898..32a4798 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1564,6 +1564,11 @@ void mmc_rescan(struct work_struct *work)
* Try SDMEM (but not MMC) even if SDIO
* is broken.
*/
+ mmc_power_up(host);
+ sdio_reset(host);
+ mmc_go_idle(host);
+ mmc_send_if_cond(host, host->ocr_avail);
+
if (mmc_send_app_op_cond(host, 0, &ocr))
goto out_fail;
--
1.7.2.3
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