linux-kernel - Re: [RFC 1/4] mmc: cqhci: Move CQHCI_ENABLE before setting TDLBA/TDLBAU

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 31 Aug 2017 09:01:34 +0300
From:   Adrian Hunter <adrian.hunter@...el.com>
To:     Ritesh Harjani <riteshh@...eaurora.org>, ulf.hansson@...aro.org
Cc:     linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org,
        stummala@...eaurora.org, asutoshd@...eaurora.org
Subject: Re: [RFC 1/4] mmc: cqhci: Move CQHCI_ENABLE before setting
 TDLBA/TDLBAU

On 30/08/17 16:04, Ritesh Harjani wrote:
> Without this patch the CQHCI registers are getting reset
> again.
> 
> Signed-off-by: Ritesh Harjani <riteshh@...eaurora.org>
> ---
>  drivers/mmc/host/cqhci.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/mmc/host/cqhci.c b/drivers/mmc/host/cqhci.c
> index 8650a13..2a7351c 100644
> --- a/drivers/mmc/host/cqhci.c
> +++ b/drivers/mmc/host/cqhci.c
> @@ -262,6 +262,9 @@ static void __cqhci_enable(struct cqhci_host *cq_host)
>  
>  	cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
>  
> +	cqcfg |= CQHCI_ENABLE;
> +	cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
That doesn't follow the flow in the specification B.6.1. Command Queuing
Initialization Sequence.  Also in B.3.5 Task List, the spec. says "Changing
the value of TDLBA is not allowed when command queue mode is enabled."

So you will need to add a quirk for this.

> +
>  	cqhci_writel(cq_host, lower_32_bits(cq_host->desc_dma_base),
>  		     CQHCI_TDLBA);
>  	cqhci_writel(cq_host, upper_32_bits(cq_host->desc_dma_base),
> @@ -271,10 +274,6 @@ static void __cqhci_enable(struct cqhci_host *cq_host)
>  
>  	cqhci_set_irqs(cq_host, 0);
>  
> -	cqcfg |= CQHCI_ENABLE;
> -
> -	cqhci_writel(cq_host, cqcfg, CQHCI_CFG);
> -
>  	mmc->cqe_on = true;
>  
>  	if (cq_host->ops->enable)
>