Re: [PATCH v2] mmc: sdhci: add quirk for broken write protect detection

2014-03-20 Thread Michal Simek
Hi, On 03/06/2014 05:42 PM, Sören Brinkmann wrote: On Thu, 2014-03-06 at 02:31PM +0100, Mike Looijmans wrote: On 03/04/2014 10:00 PM, Sören Brinkmann wrote: On Tue, 2014-03-04 at 10:06PM +0200, Eli Billauer wrote: Hello Sören, wp-inverted solves the practical problem indeed, and fools the

Re: [PATCH v2] mmc: sdhci: add quirk for broken write protect detection

2014-03-20 Thread Eli Billauer
Hello Michal. The Zybo board doesn't have any WP pin connected to the MicroSD card. There is no physical possibility for the processor to know whether the card is write-protected or not. As I mentioned earlier, the practical problem can be worked around by inverting the polarity of the WP

Re: [PATCH v2] mmc: sdhci: add quirk for broken write protect detection

2014-03-20 Thread Mike Looijmans
I totally agree with Eli. The devicetree should read something like WP is not present (which will be the case on all micro SD readers). Having WP is inverted there is just misleading. On our boards, I use MIO0 as a heartbeat LED. Combined with a quirk in XPS and/or Vivado that the pinmuxing

Re: [PATCH v2] mmc: sdhci: add quirk for broken write protect detection

2014-03-06 Thread Mike Looijmans
On 03/04/2014 10:00 PM, Sören Brinkmann wrote: On Tue, 2014-03-04 at 10:06PM +0200, Eli Billauer wrote: Hello Sören, wp-inverted solves the practical problem indeed, and fools the driver into thinking that the card has an inverted write protection sensor, and the logic zero that it finds in

Re: [PATCH v2] mmc: sdhci: add quirk for broken write protect detection

2014-03-04 Thread Sören Brinkmann
Hi Eli, On Sun, 2014-03-02 at 01:20PM +0200, Eli Billauer wrote: The write protection signal is absent on a board based upon Xilinx' Zynq processor (ZyBo). This leads the kernel to think that the MicroSD card is write protected, and causes a kernel panic during boot, as root fails to mount

Re: [PATCH v2] mmc: sdhci: add quirk for broken write protect detection

2014-03-04 Thread Eli Billauer
Hello Sören, wp-inverted solves the practical problem indeed, and fools the driver into thinking that the card has an inverted write protection sensor, and the logic zero that it finds in the hardware register means that the card isn't write protected. I'm insisting on this patch, because I

Re: [PATCH v2] mmc: sdhci: add quirk for broken write protect detection

2014-03-04 Thread Sören Brinkmann
On Tue, 2014-03-04 at 10:06PM +0200, Eli Billauer wrote: Hello Sören, wp-inverted solves the practical problem indeed, and fools the driver into thinking that the card has an inverted write protection sensor, and the logic zero that it finds in the hardware register means that the card

[PATCH v2] mmc: sdhci: add quirk for broken write protect detection

2014-03-02 Thread Eli Billauer
The write protection signal is absent on a board based upon Xilinx' Zynq processor (ZyBo). This leads the kernel to think that the MicroSD card is write protected, and causes a kernel panic during boot, as root fails to mount RW. This patch adds a quirk and an optional OF property,