Re: mmc does not work in qemu n900

["Pali Rohár" <pali.rohar@gmail.com>]

[-- Attachment #1: Type: Text/Plain, Size: 1996 bytes --]

On Tuesday 27 January 2015 10:17:39 Pali Rohár wrote:
> On Tuesday 27 January 2015 00:21:04 Aaro Koskinen wrote:
> > Hi,
> > 
> > On Mon, Jan 26, 2015 at 10:04:59PM +0100, Pali Rohár wrote:
> > > problem? Why any of these two patches fix problem when mmc
> > > is not detected by kernel in qemu (machine n900)?
> > > Detection of mmc fails because function
> > > mmc_send_op_cond() without one of above patches fails.
> > 
> > Has it ever worked? It could be just that QEMU's emulation
> > is broken. Since the kernel works on actual HW, you
> > probably should contact QEMU maintainers.
> > 
> > I don't see n900 in Debian's QEMU. There's n800 and n810 but
> > I couldn't boot any of my kernels with those...
> > 
> > A.
> 
> It worked with stock Nokia kernel (2.6.28).
> 
> N900 qemu support is not in upstream qemu project, but in
> linaro qemu version. You can find it e.g. in ubuntu:
> http://packages.ubuntu.com/source/precise-updates/qemu-linaro

Here is another alternative patch which enable internal eMMC 
support in qemu n900:

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 9584bff..225df49 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2330,13 +2330,13 @@ static int mmc_rescan_try_freq(struct 
mmc_host *host, unsigned freq)
 	sdio_reset(host);
 	mmc_go_idle(host);
 
-	mmc_send_if_cond(host, host->ocr_avail);
-
-	/* Order's important: probe SDIO, then SD, then MMC */
-	if (!mmc_attach_sdio(host))
-		return 0;
-	if (!mmc_attach_sd(host))
-		return 0;
+//	mmc_send_if_cond(host, host->ocr_avail);
+//
+//	/* Order's important: probe SDIO, then SD, then MMC */
+//	if (!mmc_attach_sdio(host))
+//		return 0;
+//	if (!mmc_attach_sd(host))
+//		return 0;
 	if (!mmc_attach_mmc(host))
 		return 0;
 
It just disable SDIO and SD code. It looks like using some SDIO 
or SD commands on mmc controller in qemu cause problems...

Any idea?

-- 
Pali Rohár
pali.rohar@gmail.com

[-- Attachment #2: This is a digitally signed message part. --]
[-- Type: application/pgp-signature, Size: 198 bytes --]