Bit 3 of the SR register is set if there is a tx underrun. If this bit isn't set, we should loop on the tx ready bit until we can transmit again. Otherwise we should skip the loop and transmit immediately. The code is doing the opposite though, checking for an underrun and then looping on the tx ready bit causing us to never loop on the tx read bit when the tx buffer may not be ready. This doesn't seem to affect my 8960 device too often, but in some cases I see a lost character or two from the decompressor prints. This also matches what we do in the assembly in debug-macro.S. Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> --- Nobody has noticed this so far so I'm ok waiting for 3.10 on this one. Also it doesn't improve stability (debug feature) so I don't see a reason to send it to stable. arch/arm/mach-msm/include/mach/uncompress.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mach-msm/include/mach/uncompress.h b/arch/arm/mach-msm/include/mach/uncompress.h index fa97a10..9432487 100644 --- a/arch/arm/mach-msm/include/mach/uncompress.h +++ b/arch/arm/mach-msm/include/mach/uncompress.h @@ -37,7 +37,7 @@ static void putc(int c) * Wait for TX_READY to be set; but skip it if we have a * TX underrun. */ - if (UART_DM_SR & 0x08) + if (!(UART_DM_SR & 0x08)) while (!(UART_DM_ISR & 0x80)) cpu_relax(); -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
