From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Date: Tue, 06 Nov 2012 09:31:44 +0900 Subject: [U-Boot] [PATCH 2/3] mmc: sdhci: add the DMA select for SDMA In-Reply-To: <20121105133827.GA62571@crg> References: <505C09DB.20403@samsung.com> <20121105133827.GA62571@crg> Message-ID: <50985A70.8010703@samsung.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Hi Rommel, Thanks for report. On 11/05/2012 10:39 PM, Rommel G Custodio wrote: > Dear All, Jaehoon Chung > > On 2012.09/21, Jaehoon Chung wrote: >> In host-control register, DMA select bit field is present. >> BUt in sdhci.c, didn't select for DMA. > > This is an FYI. > Maybe others will encounter the same problem I had. > > This code has recently been mainlined and it has caused some problems in > the IP that I am working with. The IP hangs when this code is enabled. How did you hang your IP when this code is enabled? Before enabled, also set to SDMA_MODE at HOST_CONTROL register. Just More exactly to set SDMA mode is used this code. Is your IP using other DMA mode? Just i want to know your hang case. Best Regards, Jaehoon Chung > >> if set CONFIG_MMC_SDMA, we need to set SDMA-select bit. > > The bit in the SDHCI specs show that 00b is the code for choosing SDMA. > So this code is not really necessary as long as sdhci_init() or sdhci_set_ios(), > the API that modifies SDHCI_HOST_CONTROL, does not touch the DMA bits. Right now, > by looking at the code, sdhci_init() nor sdhci_set_ios() does not modify the DMA > bits. > >> >> Signed-off-by: Jaehoon Chung >> Signed-off-by: Kyungmin Park > > All the best, > Rommel >