> -----Original Message----- > From: Tomi Valkeinen [mailto:tomi.valkeinen@xxxxxxxxx] > Sent: Monday, July 26, 2010 3:50 PM > To: Taneja, Archit > Cc: linux-omap@xxxxxxxxxxxxxxx > Subject: Re: DSS2: DSI: Check for TX FIFO emptiness when > sending long packets > > On Mon, 2010-07-26 at 11:28 +0200, ext Taneja, Archit wrote: > > Hi, > > > > I had a little query. We check for TX FIFO not full before > sending a > > short packet in dsi_vc_send_short(), but we don't have a > similar check > > in dsi_vc_send_long() before writing to the long packet header. > > > > There is a check of the static fifo size of the channel and > the length > > of data we are pushing, but that does not reflect the state > of the TX > > FIFO at that point of time. > > > > Do you think we should have a check using DSI_TX_FIFO_VC_EMPTINESS > > before writing to the long packet header? > > Yes, I think we should check that. Otherwise the transfer > will break with DSI_VC_IRQ_FIFO_TX_OVF interrupt, although I > think the lcd driver doesn't currently see this in any way. Yes, the maximum number of bytes we send to taal panel using this fucntion is 5 bytes, hence it is quite unlikely to get a fifo overflow. > Although I'm not sure which would be better, return an error (EBUSY? > EWOULDBLOCK?) if the FIFO cannot hold the whole message, or > block until the FIFO can hold the whole message... > Tomi > I am not sure about this, it can be probably aligned with what is done in update_screen_l4(). I didn't exaclty get why you block till fifo_stalls > 0xfffff and if we can have a similar reasoning for send_long? It would be great though if we can make dsi_vc_send_long() configurable enough to be actually used in dsi_update_screen_l4(), because they both have enough common code beween them. Thanks, Archit -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
