From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaehoon Chung Date: Fri, 24 May 2013 15:46:29 +0900 Subject: [U-Boot] [PATCH] MMC: DWMMC: Fix FIFO_DEPTH calculation In-Reply-To: References: <1369314900-16412-1-git-send-email-rajeshwari.s@samsung.com> <519EC59E.1070002@samsung.com> Message-ID: <519F0CC5.6090504@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 Jagan, On 05/24/2013 03:15 PM, Rajeshwari Birje wrote: > Hi Jagan, > > Please find my comments below. > On Fri, May 24, 2013 at 10:31 AM, Jagan Teki wrote: >> On Fri, May 24, 2013 at 7:12 AM, Jaehoon Chung wrote: >>> On 05/24/2013 03:27 AM, Jagan Teki wrote: >>>> On Thu, May 23, 2013 at 6:45 PM, Rajeshwari Shinde >>>> wrote: >>>>> Current DWMMC driver used to give FIFO underrun/overrun error every 3rd time >>>>> for mmc rescan command. >>>>> In current code FIFO_DEPTH is getting calculated after reading the FIFOTH >>>>> register and extracting the RX_WMARK bits from it i.e (RX_WMARK = FIFO_DEPTH/2 -1). >>>>> Instead of storing the correct value, we were recalculating the FIFO_DEPT each >>>>> time which is not correct. >>>>> >>>>> Signed-off-by: Hatim Ali >>>>> Signed-off-by: Rajeshwari Shinde >>>>> --- >>>>> drivers/mmc/dw_mmc.c | 6 ++++-- >>>>> 1 files changed, 4 insertions(+), 2 deletions(-) >>>>> >>>>> diff --git a/drivers/mmc/dw_mmc.c b/drivers/mmc/dw_mmc.c >>>>> index 4070d4e..be590a4 100644 >>>>> --- a/drivers/mmc/dw_mmc.c >>>>> +++ b/drivers/mmc/dw_mmc.c >>>>> @@ -332,11 +332,13 @@ static int dwmci_init(struct mmc *mmc) >>>>> dwmci_writel(host, DWMCI_BMOD, 1); >>>>> >>>>> fifo_size = dwmci_readl(host, DWMCI_FIFOTH); >>>>> - if (host->fifoth_val) >>>>> + if (host->fifoth_val) { >>>> >>>> What is the inital value for host->fifoth_val, for the first time call.? >>> It should be set into board-specific file(dw-mmc_exynos.c) or others. >> >> I am unable to find dw-mmc_exynos.c on the master, and also I haven't >> see fifoth_val used other than dw_mmc.c >> Could you please help me out. > dw-mmc_exynos.c is merged in mmc tree. Yes FIFO_DEPTH is set only in dw_mmc.c host->fifoth_val should be set to hard-coding by developer. In general case, it's right that fifoth_Val is calculated with register value. But sometime, it needs to set to other value, not register value. Then we can use the host->fifoth_val in board-specific file. Maybe it didn't use the host->fifoth_val anywhere. In future, we can use this. Best Regards, Jaehoon Chung >> >> Thanks, >> Jagan. >> >>> >>> Best Regards, >>> Jaehoon Chung >>>> >>>>> fifoth_val = host->fifoth_val; >>>>> - else >>>>> + } else { >>>>> fifoth_val = MSIZE(0x2) | RX_WMARK(fifo_size/2 -1) | >>>>> TX_WMARK(fifo_size/2); >>>>> + host->fifoth_val = fifoth_val; >>>>> + } >>>>> dwmci_writel(host, DWMCI_FIFOTH, fifoth_val); >>>>> >>>>> dwmci_writel(host, DWMCI_CLKENA, 0); >>>>> -- >>>>> 1.7.4.4 >>>>> >>>> >>>> Thanks, >>>> Jagan. >>>> >>> >> _______________________________________________ >> U-Boot mailing list >> U-Boot at lists.denx.de >> http://lists.denx.de/mailman/listinfo/u-boot >