From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Hannemann Date: Tue, 07 Dec 2010 12:22:22 +0000 Subject: Re: [PATCH 1/4] mmc: tmio: Implement SDIO IRQ Message-Id: <4CFE26FE.2070206@arndnet.de> List-Id: References: <1291656942-18100-1-git-send-email-arnd@arndnet.de> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Magnus Damm Cc: linux-mmc@vger.kernel.org, linux-sh@vger.kernel.org, g.liakhovetski@gmx.de, Ian Molton , Samuel Ortiz Hi Magnus, Am 07.12.2010 00:39, schrieb Magnus Damm: > Hi Arnd, > > On Tue, Dec 7, 2010 at 2:35 AM, Arnd Hannemann wrote: >> This patch implements SDIO IRQ support for mfds which >> announce the MMC_CAP_SDIO_IRQ capability for tmio_mmc. >> Tested with a b43-based wireless SDIO card and sh_mobile_sdhi. >> >> This patch applies on top of: >> mmc: tmio_mmc: allow multi-element scatter-gather lists >> mmc: tmio_mmc: fix PIO fallback on DMA descriptor allocation failure >> mmc: tmio: merge the private header into the driver >> mmc: tmio: implement a bounce buffer for unaligned DMA >> >> Signed-off-by: Arnd Hannemann >> CC: Ian Molton >> CC: Samuel Ortiz >> CC: Guennadi Liakhovetski >> --- >> drivers/mmc/host/tmio_mmc.c | 54 ++++++++++++++++++++++++++++++++++++++++++- >> 1 files changed, 53 insertions(+), 1 deletions(-) > > Thanks for your work on this! > > Just curious, did you test this change in 4-bit mode and/or 1-bit > mode? I believe that 1-bit mode support is rather simple, but 4-bit > mode requires toggling between the IRQ and DATA function which happen > to be using the same pin. It looks like the current code only deals > with 1-bit mode - perhaps 4-bit mode isn't supported by the b43 > driver? Yes, I tested this in 1-bit and 4-bit mode. At least the card claims it is using it, it says "width=2". I also read about the toggling, and expected to do something fancy, but when tests where successful I came to the conclusion that the controller does the toggling for us. Do you believe otherwise? > Not sure how the Linux MMC stack supports 4-bit IRQs, but the S4MI bit > in the CCCR should specify if it's allowed to enable interrupts in > between data transfers or not. Perhaps that is something we need to > deal with in the driver? Or maybe the framework needs to be extended? I quick grep shows that nobody seems to care about this bit until now... Thanks, Arnd