Re: [PATCHv2 4/5] mmc: shdci-bcm2835: add verify for 32-bit back-to-back workaround

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Hi Scott,

Am 22.12.2015 um 20:23 schrieb Scott Branden:
Hi Stefan,

On 15-12-22 07:55 AM, Stefan Wahren wrote:
Hi Scott,

Am 07.11.2014 um 19:31 schrieb Scott Branden:
On 14-11-05 09:01 PM, Stephen Warren wrote:
On 11/05/2014 12:00 AM, Scott Branden wrote:
On 14-11-04 08:59 PM, Stephen Warren wrote:
On 10/30/2014 12:36 AM, Scott Branden wrote:
Add a verify option to driver to print out an error message if a
potential back to back write could cause a clock domain issue.

index f8c450a..11af27f 100644

+#ifdef CONFIG_MMC_SDHCI_BCM2835_VERIFY_WORKAROUND
+    struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+    struct bcm2835_sdhci_host *bcm2835_host = pltfm_host->priv;
+
+    if (bcm2835_host->previous_reg == reg) {
+        if ((reg != SDHCI_HOST_CONTROL)
+            && (reg != SDHCI_CLOCK_CONTROL)) {

The comment in patch 3 says the problem doesn't apply to the data
register. Why does this check for these two registers rather than
data?
This Verify workaround patch still a work in progress.  I'm still
getting more info from the silicon designers on the back-to-back
register writes that are affect.  The spew of 0x20 or 0x28 or 0x2c
register writes are all ok locations that don't need to be worked
around.  This patch needs to be corrected with the proper register
rules
still.
Thanks for testing.  Yes, I have work to do on the verify patch above
still.

do you still have plans to submit a V3 of this patch series?
No, I do not have plans to submit a V3 of this patch series.

I submitted this patch as RPI has a similar controller to the SoCs I am
familiar with as well as needing similar work arounds   You can take
over the patchset.  Or, try and get the sdhci-iproc.c driver going on
RPI.  The sdhci-iproc is the production driver we use on a variety of
SoCs and support and test this driver.

after applying the patch series both drivers are very similiar so i prefer the latter. I will give it a try. Thanks for the hint about sdhci-iproc.

Regards
Stefan


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