From mboxrd@z Thu Jan 1 00:00:00 1970 From: jaswinder.singh@linaro.org (Jassi Brar) Date: Wed, 24 Apr 2013 13:29:46 +0530 Subject: [PATCHv3 00/14] drivers: mailbox: framework creation In-Reply-To: <51778C3B.7010501@st.com> References: <1363145021-14339-1-git-send-email-s-anna@ti.com> <37C860A02101E749A747FA2D3C1E3C504A5DF7@DLEE11.ent.ti.com> <37C860A02101E749A747FA2D3C1E3C504A63B4@DLEE11.ent.ti.com> <51778C3B.7010501@st.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Loic, On 24 April 2013 13:09, Loic PALLARDY wrote: > Hi Jassi, Suman, > > Yes, the xxx_no_irq API has been introduced to answer some STE > requirements. It must be possible to send some message under atomic > context for different reasons (latency, during idle/suspend procedures...). > This is not the best way to do, but the goal was to preserve TI legacy > in a first step. As explained by Suman, this patch series is coming from > the original TI mailbox framework and is modified step by step to fit > with all platforms. > IMHO a better way is to introduce a clean generically designed API and convert the existing drivers one at time. Let the TI drivers work as such for a while until someone converts them to the common API. Cloning and then complete organ transplantation seems a very inefficient way to have something new ;) >>> >>> (d) The 'struct mailbox_msg' should be just an opaque void* - the client/protocol >>> driver typecasts to void* the IPC controller specific message structure. API >>> shouldn't aim the impossible of providing a generic message format. >> >> The size parameter would still be needed. Depending on the h/w, it can be just an u32 or a series of bytes, and even in the latter case, it is not guaranteed that all messages transmitted will occupy the entire h/w shared memory data packet. I can see the current header field getting absorbed into the opaque void * structure for the ST mailbox driver. The size and ptr together provide a very generic message format. > That's something we discussed with Suman. The mailbox framework should > be independent from message format. Since mailbox could be base don a > shared mem or an hw fifo, message size is mandatory to transmit the > right number of data. > I too believe the "mailbox framework should be independent from message format" but _also_ that .size doesn't have to be a part of the standard format. Maybe it will help if I know what you guys mean by "shared mem" or an "hw fifo" mailbox? Thanks -Jassi