On 07/22/2010 04:34 PM, Jassi Brar wrote: > On Thu, Jul 22, 2010 at 10:18 PM, Tejun Heo <tj@xxxxxxxxxx> wrote: >> It's been a while since I read pci-e spec but IIUC readrq size and >> payload size are independent and if readrq is larger than payload size >> it's supposed to complete in multiple steps. I could be wrong tho. > AFAIUI readrq size is independent and not greater than the max_payload size. > Payload size is what max a device can handle and readrq is what a device can > ask. > SIL24 does support 4096 and hence can set readrq to that limit, but if the > payload capacity of the RC is less than 4096, I am not sure if it is supposed to > work. Hmm... my impression is that a single read request may be served by multiple TLPs, so readrq size can go over payload size which limits the size of payload in a single TLP, but let's wait for someone more knowledgeable to chime in. Thanks. -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
